diff --git a/fastapi-vue/fastapi_vue/__init__.py b/fastapi-vue/fastapi_vue/__init__.py
index 5409b89..fbbb0e5 100644
--- a/fastapi-vue/fastapi_vue/__init__.py
+++ b/fastapi-vue/fastapi_vue/__init__.py
@@ -1,3 +1,5 @@
+"""FastAPI Vue integration - serve Vue frontend from FastAPI."""
+
 from .staticfiles import Frontend
 
 __all__ = ["Frontend"]
diff --git a/fastapi-vue/fastapi_vue/hostutil.py b/fastapi-vue/fastapi_vue/hostutil.py
index 50bee9b..9364788 100644
--- a/fastapi-vue/fastapi_vue/hostutil.py
+++ b/fastapi-vue/fastapi_vue/hostutil.py
@@ -1,8 +1,60 @@
+"""Parse endpoint strings for uvicorn server configuration."""
+
 import contextlib
 import ipaddress
 from urllib.parse import urlparse
 
 
+def _parse_all_interfaces(value: str) -> list[dict] | None:
+    """Parse ':port' format to bind all interfaces."""
+    if not (value.startswith(":") and value != ":"):
+        return None
+    port_part = value[1:]
+    if not port_part.isdigit():
+        msg = f"Invalid port in '{value}'"
+        raise SystemExit(msg)
+    port = int(port_part)
+    return [{"host": "0.0.0.0", "port": port}, {"host": "::", "port": port}]  # noqa: S104
+
+
+def _parse_unix_socket(value: str) -> list[dict] | None:
+    """Parse UNIX domain socket paths."""
+    if value.startswith("/"):
+        return [{"uds": value}]
+    if value.startswith("unix:"):
+        uds_path = value[5:] or None
+        if uds_path is None:
+            msg = "unix: path must not be empty"
+            raise SystemExit(msg)
+        return [{"uds": uds_path}]
+    return None
+
+
+def _parse_unbracketed_ipv6(value: str, default_port: int) -> list[dict] | None:
+    """Parse unbracketed IPv6 addresses."""
+    if value.count(":") <= 1 or value.startswith("["):
+        return None
+    try:
+        ipaddress.IPv6Address(value)
+    except ValueError as e:
+        msg = f"Invalid IPv6 address '{value}': {e}"
+        raise SystemExit(msg) from e
+    return [{"host": value, "port": default_port}]
+
+
+def _parse_host_port(value: str, default_port: int) -> list[dict]:
+    """Parse host[:port] or [ipv6][:port] using urlparse."""
+    parsed = urlparse(f"//{value}")  # // prefix lets urlparse treat it as netloc
+    host = parsed.hostname or "localhost"
+    port = parsed.port or default_port
+
+    # Validate IP literals (optional; hostname passes through)
+    with contextlib.suppress(ValueError):
+        ipaddress.ip_address(host)
+
+    return [{"host": host, "port": port}]
+
+
 def parse_endpoint(value: str | None, default_port: int = 0) -> list[dict]:
     """Parse an endpoint string into uvicorn bind configurations.
 
@@ -23,6 +75,7 @@ def parse_endpoint(value: str | None, default_port: int = 0) -> list[dict]:
     - [ipv6]:port -> [{host: ipv6, port}]
     - ipv6 (unbracketed) -> [{host: ipv6, port: default_port}]
     - /path or unix:/path -> [{uds: path}]
+
     """
     if not value:
         return [{"host": "localhost", "port": default_port}]
@@ -31,51 +84,33 @@ def parse_endpoint(value: str | None, default_port: int = 0) -> list[dict]:
     if value.isdigit():
         return [{"host": "localhost", "port": int(value)}]
 
-    # Leading colon :port -> bind all interfaces (0.0.0.0 + ::)
-    if value.startswith(":") and value != ":":
-        port_part = value[1:]
-        if not port_part.isdigit():
-            raise SystemExit(f"Invalid port in '{value}'")
-        port = int(port_part)
-        return [{"host": "0.0.0.0", "port": port}, {"host": "::", "port": port}]  # noqa: S104
+    # Try specialized parsers in order
+    result = _parse_all_interfaces(value)
+    if result is not None:
+        return result
 
-    # UNIX domain socket (unix:/path or just /path)
-    if value.startswith("/"):
-        return [{"uds": value}]
-    if value.startswith("unix:"):
-        uds_path = value[5:] or None
-        if uds_path is None:
-            raise SystemExit("unix: path must not be empty")
-        return [{"uds": uds_path}]
+    result = _parse_unix_socket(value)
+    if result is not None:
+        return result
 
-    # Unbracketed IPv6 (cannot safely contain a port) -> detect by multiple colons
-    if value.count(":") > 1 and not value.startswith("["):
-        try:
-            ipaddress.IPv6Address(value)
-        except ValueError as e:
-            raise SystemExit(f"Invalid IPv6 address '{value}': {e}") from e
-        return [{"host": value, "port": default_port}]
+    result = _parse_unbracketed_ipv6(value, default_port)
+    if result is not None:
+        return result
 
-    # Use urllib.parse for everything else (host[:port], [ipv6][:port])
-    parsed = urlparse(f"//{value}")  # // prefix lets urlparse treat it as netloc
-    host = parsed.hostname or "localhost"
-    port = parsed.port or default_port
-
-    # Validate IP literals (optional; hostname passes through)
-    with contextlib.suppress(ValueError):
-        ipaddress.ip_address(host)
-
-    return [{"host": host, "port": port}]
+    # Fallback: host[:port], [ipv6][:port]
+    return _parse_host_port(value, default_port)
 
 
 def parse_endpoints(
-    listen: str | list[str] | None = None, default_port: int = 8000
+    listen: str | list[str] | None = None,
+    default_port: int = 8000,
 ) -> list[dict]:
     """Parse listen strings into a list of endpoint dicts.
 
     Args:
         listen: Endpoint string(s) (see parse_endpoint for formats).
         default_port: Port to use when not specified in listen args.
+
     """
     if listen is None:
         listen = [f"localhost:{default_port}"]
diff --git a/fastapi-vue/fastapi_vue/server.py b/fastapi-vue/fastapi_vue/server.py
index dd7fae6..70c8443 100644
--- a/fastapi-vue/fastapi_vue/server.py
+++ b/fastapi-vue/fastapi_vue/server.py
@@ -1,7 +1,10 @@
+"""Uvicorn server runner with multi-endpoint support."""
+
 import asyncio
 import logging
 import os
 from contextlib import suppress
+from typing import Any
 
 import uvicorn
 from uvicorn import Config, Server
@@ -18,8 +21,8 @@ def run(
     default_port: int = 8000,
     reload: bool = False,
     workers: int | None = None,
-    **uvicorn_config,
-):
+    **uvicorn_config: Any,  # noqa: ANN401
+) -> None:
     """Run uvicorn server(s) for the given app.
 
     Args:
@@ -29,10 +32,12 @@ def run(
         reload: Enable auto-reload (requires uvicorn.run, single endpoint only).
         workers: Number of worker processes (requires uvicorn.run, single endpoint only).
         **uvicorn_config: Additional uvicorn config options (overrides all other settings).
+
     """
     endpoints = parse_endpoints(listen, default_port)
     if not endpoints:
-        raise ValueError("No endpoints to serve; check listen configuration")
+        msg = "No endpoints to serve; check listen configuration"
+        raise ValueError(msg)
 
     conf: dict[str, object] = {"app": app, "reload": reload, "workers": workers}
     proxy = os.getenv("FORWARDED_ALLOW_IPS", "127.0.0.1,::1")
@@ -48,7 +53,7 @@ def run(
             asyncio.run(serve(endpoints, **conf))
 
 
-async def serve(endpoints: list[dict], **kwargs) -> None:
+async def serve(endpoints: list[dict], **kwargs: Any) -> None:  # noqa: ANN401
     """Serve the given endpoints in current process/loop. Does not spawn extra processes."""
     forbidden = {"reload", "workers"} & {k for k, v in kwargs.items() if v}
     if forbidden:
@@ -59,13 +64,10 @@ async def serve(endpoints: list[dict], **kwargs) -> None:
     await asyncio.gather(*(Server(Config(**kwargs, **ep)).serve() for ep in endpoints))
 
 
-def serve_multiprocess(endpoints: list[dict], **kwargs) -> None:
+def serve_multiprocess(endpoints: list[dict], **kwargs: Any) -> None:  # noqa: ANN401
     """Serve using uvicorn.run() for reload/workers support. Only first endpoint is used."""
     if len(endpoints) > 1:
-        eps = [
-            ep["uds"] if "uds" in ep else f"{ep['host']}:{ep['port']}"
-            for ep in endpoints
-        ]
+        eps = [ep["uds"] if "uds" in ep else f"{ep['host']}:{ep['port']}" for ep in endpoints]
         logger.warning(
             "Current mode supports only one endpoint. Listening: %s, skipped: %s",
             eps[0],
diff --git a/fastapi-vue/fastapi_vue/staticfiles.py b/fastapi-vue/fastapi_vue/staticfiles.py
index 9290881..252f3c9 100644
--- a/fastapi-vue/fastapi_vue/staticfiles.py
+++ b/fastapi-vue/fastapi_vue/staticfiles.py
@@ -25,7 +25,7 @@ __all__ = ["Frontend"]
 
 
 class Assets:
-    """Default cached value to /assets/"""
+    """Default cached value to /assets/."""
 
     @staticmethod
     def parse(cached: str | list[str] | Assets) -> list[str]:
@@ -37,7 +37,8 @@ class Assets:
             case list():
                 return cached
             case _:
-                raise ValueError(f"Invalid cached value: {cached!r}")
+                msg = f"Invalid cached value: {cached!r}"
+                raise ValueError(msg)
 
 
 class Frontend:
@@ -55,27 +56,29 @@ class Frontend:
         index: Name of the index file (default: "index.html")
         spa: Enable SPA mode - serve index.html for unknown routes (default: False)
         cached: Path prefixes that are immutable (default: "/assets/")
-        favicon: May use wildcards of full path. E.g. /assets/logo*.png matches logo.hash.png created by Vite
+        favicon: Wildcard path to favicon. E.g. /assets/logo*.png matches Vite output
         zstdlevel: Zstd compression level (default: 18)
+
     """
 
-    def __init__(
+    def __init__(  # noqa: PLR0913
         self,
         directory: Path | str,
         *,
         index: str = "index.html",
         spa: bool = False,
         catch_all: bool | None = None,
-        cached: str | list[str] | Assets = Assets(),
+        cached: str | list[str] | Assets | None = None,
         favicon: str | None = None,
         zstdlevel: int = 18,
     ) -> None:
+        """Initialize Frontend with given configuration."""
         self.www: dict[str, tuple[bytes, bytes | None, dict]] = {}
         self.base: Path = Path(directory)
         self.index = index
         self.spa = spa
         self._catch_all = spa if catch_all is None else catch_all
-        self.cached_paths = Assets.parse(cached)
+        self.cached_paths = Assets.parse(cached if cached is not None else Assets())
         self.zstdlevel = zstdlevel
         self.favicon = favicon
         self._app: FastAPI | None = None
@@ -107,11 +110,12 @@ class Frontend:
                 paths.add("/favicon.ico")
         return paths
 
-    def _load(self):
+    def _load(self) -> dict[str, tuple[bytes, bytes | None, dict]]:
         """Load static files from disk with compression."""
         www: dict[str, tuple[bytes, bytes | None, dict]] = {}
         if not self.base.exists():
-            raise ValueError(f"Frontend folder {self.base} not found (try uv build)")
+            msg = f"Frontend folder {self.base} not found (try uv build)"
+            raise ValueError(msg)
         paths = [PurePath()]
         while paths:
             current = self.base / paths.pop(0)
@@ -133,21 +137,18 @@ class Frontend:
                 headers = {
                     "etag": f'"{etag}"',
                     "last-modified": format_date_time(mtime),
-                    "cache-control": (
-                        "max-age=31536000, immutable" if cached else "no-cache"
-                    ),
+                    "cache-control": ("max-age=31536000, immutable" if cached else "no-cache"),
                     "content-type": mime,
                 }
                 zstd = ZstdCompressor(self.zstdlevel).compress(data)
                 if len(zstd) >= len(data):
                     zstd = None
                 www[name] = data, zstd, headers
-        if self.favicon:
-            if m := fnmatch.filter(www, self.favicon):
-                data, zstd, headers = www[m[0]]
-                if "immutable" in headers.get("cache-control", ""):
-                    headers = {**headers, "cache-control": "max-age=86400"}
-                www["/favicon.ico"] = data, zstd, headers
+        if self.favicon and (m := fnmatch.filter(www, self.favicon)):
+            data, zstd, headers = www[m[0]]
+            if "immutable" in headers.get("cache-control", ""):
+                headers = {**headers, "cache-control": "max-age=86400"}
+            www["/favicon.ico"] = data, zstd, headers
         if not www:
             msg = "Frontend files missing, check your installation.\n"
             www["/"] = (
@@ -161,7 +162,7 @@ class Frontend:
             )
         return www
 
-    async def load(self, *, debug: bool | None = None, log: bool = True):
+    async def load(self, *, debug: bool | None = None, log: bool = True) -> None:
         """Load or reload static files from disk.
 
         In debug mode, returns 409 instead of files (avoid accidental use of stale builds)
@@ -187,13 +188,19 @@ class Frontend:
         ratio = comp / raw * 100 if raw else 100.0
         if log and self.www:
             logger.info(
-                f"{self.base.name}: {len(self.www)} files in {1000 * duration:.1f} ms | "
-                f"zstd {len(compfiles)} files {1e-6 * raw:.2f}->{1e-6 * comp:.2f} MB ({ratio:.0f} %)"
+                "%s: %d files in %.1f ms | zstd %d files %.2f->%.2f MB (%.0f %%)",
+                self.base.name,
+                len(self.www),
+                1000 * duration,
+                len(compfiles),
+                1e-6 * raw,
+                1e-6 * comp,
+                ratio,
             )
         if self.favicon and "/favicon.ico" not in self.www:
             logger.warning("Favicon not found: %s", self.favicon)
 
-    def route(self, app: FastAPI, mount_path="/"):
+    def route(self, app: FastAPI, mount_path: str = "/") -> None:
         """Register frontend routes with a FastAPI app.
 
         In SPA/catch-all mode, this must only be called only after all other routes.
@@ -204,6 +211,7 @@ class Frontend:
         Args:
             app: FastAPI application instance
             mount_path: Path where the frontend should be mounted (default: "/")
+
         """
         self._app = app
         self._mount_path = mount_path.rstrip("/")
@@ -214,7 +222,7 @@ class Frontend:
             path = self._mount_path + "{path:path}"
             app.api_route(path, methods=["GET", "HEAD"], name="frontend")(self.handle)
 
-    def _register_routes(self):
+    def _register_routes(self) -> None:
         """Register individual routes for each loaded file (non-catch_all mode)."""
         if self._app is None or self._catch_all:
             return
@@ -240,18 +248,19 @@ class Frontend:
             for p in paths
         ]
 
-    def _respond(self, request: Request, name: str):
+    def _respond(self, request: Request, name: str) -> Response:
         """Serve a static file with ETag and compression support."""
         data, zstd, headers = self.www[name]
         if request.headers.get("if-none-match") == headers["etag"]:
             return Response(status_code=304, headers=headers)
         if zstd and "zstd" in request.headers.get("accept-encoding", ""):
             return Response(
-                content=zstd, headers={**headers, "content-encoding": "zstd"}
+                content=zstd,
+                headers={**headers, "content-encoding": "zstd"},
             )
         return Response(content=data, headers=headers)
 
-    def handle(self, request: Request, path: str):
+    def handle(self, request: Request, path: str) -> Response | RedirectResponse:
         """SPA catch-all handler with directory redirects and fallback to index."""
         name = path.removesuffix(self.index)
         debug = getattr(self._app, "debug", False)
@@ -271,11 +280,9 @@ class Frontend:
         return (_devmode_respond if debug else self._respond)(request, name)
 
 
-def _devmode_respond(request: Request, name=""):
+def _devmode_respond(_request: Request, _name: str = "") -> JSONResponse:
     """Return error response directing to Vite server."""
     return JSONResponse(
         status_code=409,
-        content={
-            "detail": "[devmode] Not serving frontend files here. Should you connect to Vite instead?"
-        },
+        content={"detail": "[devmode] Use Vite devserver instead."},
     )
diff --git a/fastapi_vue_setup.py b/fastapi_vue_setup.py
index 1dddcd0..8401d51 100644
--- a/fastapi_vue_setup.py
+++ b/fastapi_vue_setup.py
@@ -1,4 +1,4 @@
-"""FastAPI-Vue Integration Tool
+"""FastAPI-Vue Integration Tool.
 
 Create new FastAPI+Vue projects or patch existing ones with integrated build/dev systems.
 
@@ -13,8 +13,11 @@ Options:
 
 import argparse
 import ast
+import contextlib
+import hashlib
 import importlib.metadata
 import os
+import platform
 import re
 import shutil
 import subprocess
@@ -53,46 +56,59 @@ def ruff_format_content(
     temp_file = target_path.with_suffix(".new.py")
     try:
         temp_file.write_text(content, "UTF-8", newline="\n")
-        # Sort imports first
-        subprocess.run(
-            [
-                "uv",
-                "run",
-                "--with",
-                "ruff",
+        if mode == "isort":
+            # Sort imports only (ignore exit code)
+            result = subprocess.run(  # noqa: S603
+                [  # noqa: S607
+                    "ruff",
+                    "check",
+                    "--select",
+                    "I",
+                    "--fix",
+                    "--output-format=concise",
+                    str(temp_file),
+                ],
+                cwd=target_path.parent,
+                capture_output=True,
+                check=False,
+            )
+            if result.returncode != 0:
+                print(result.stdout.decode())
+            return temp_file.read_text("UTF-8")
+        # Full mode: fix all auto-fixable lint violations (ignore exit code)
+        result = subprocess.run(  # noqa: S603
+            [  # noqa: S607
                 "ruff",
                 "check",
-                "--select",
-                "I",
                 "--fix",
+                "--output-format=concise",
                 str(temp_file),
             ],
             cwd=target_path.parent,
             capture_output=True,
+            check=False,
         )
-        if mode == "isort":
-            return temp_file.read_text("UTF-8")
-        # Then format
-        result = subprocess.run(
-            ["uv", "run", "--with", "ruff", "ruff", "format", str(temp_file)],
+        if result.returncode != 0:
+            print(result.stdout.decode())
+        # Then format (ignore exit code)
+        result = subprocess.run(  # noqa: S603
+            ["ruff", "format", str(temp_file)],  # noqa: S607
             cwd=target_path.parent,
             capture_output=True,
+            check=False,
         )
-        if result.returncode == 0:
-            return temp_file.read_text("UTF-8")
-    except Exception:
+        if result.returncode != 0:
+            print(result.stdout.decode())
+        return temp_file.read_text("UTF-8")
+    except OSError:
         pass
     finally:
-        try:
+        with contextlib.suppress(Exception):
             temp_file.unlink(missing_ok=True)
-        except Exception:
-            pass
     return content
 
 
-def uv_add_packages(
-    packages: list[str], *, cwd: Path, group: str | None = None
-) -> None:
+def uv_add_packages(packages: list[str], *, cwd: Path, group: str | None = None) -> None:
     """Add packages using uv."""
     cmd = ["uv", "add", "-q", "-U"]
     if group:
@@ -100,7 +116,7 @@ def uv_add_packages(
     else:
         cmd.append("--no-sync")
     cmd.extend(packages)
-    result = subprocess.run(cmd, cwd=cwd, check=False)
+    result = subprocess.run(cmd, cwd=cwd, check=False)  # noqa: S603
     if result.returncode != 0:
         label = f" ({group})" if group else ""
         print(f"⚠️  Failed to add{label} dependencies")
@@ -126,9 +142,7 @@ PYPROJECT_ADDITIONS = {
                 "artifacts": ["MODULE_NAME/frontend-build"],
                 "targets": {
                     "sdist": {
-                        "hooks": {
-                            "custom": {"path": "scripts/fastapi-vue/build-frontend.py"}
-                        },
+                        "hooks": {"custom": {"path": "scripts/fastapi-vue/build-frontend.py"}},
                     }
                 },
                 "only-packages": True,
@@ -236,7 +250,8 @@ def parse_ports(ports_str: str | None) -> tuple[int, int, int]:
         vite = int(parts[1])
         dev = int(parts[2])
     else:
-        raise ValueError(f"Invalid ports format: {ports_str}")
+        msg = f"Invalid ports format: {ports_str}"
+        raise ValueError(msg)
 
     # Auto-adjust dev if it conflicts with vite
     if dev == vite:
@@ -263,9 +278,7 @@ def find_import_insertion_line(source: str) -> int:
     return 2 if source.startswith("#!") else 1
 
 
-def extract_existing_ports(
-    project_dir: Path, main: Path
-) -> tuple[int, int, int] | None:
+def extract_existing_ports(project_dir: Path, main: Path) -> tuple[int, int, int] | None:
     """Extract existing port configuration from project files.
 
     Returns (default, vite, dev) or None if not found.
@@ -313,6 +326,7 @@ def extract_existing_health(project_dir: Path) -> str | object:
     Returns:
         - The path string (may be empty to disable)
         - _HEALTH_NOT_FOUND sentinel if not found or file doesn't exist
+
     """
     devserver_file = project_dir / "scripts" / "devserver.py"
     if not devserver_file.exists():
@@ -346,9 +360,7 @@ def find_module_name(project_dir: Path) -> str | None:
     return None
 
 
-def find_fastapi_app(
-    module_dir: Path, project_dir: Path | None = None
-) -> tuple[Path, str] | None:
+def find_fastapi_app(module_dir: Path, project_dir: Path | None = None) -> tuple[Path, str] | None:
     """Find the FastAPI app in a module directory.
 
     Returns (file_path, app_variable_name) or None if not found.
@@ -386,9 +398,7 @@ def find_fastapi_app(
     return None
 
 
-def _find_app_via_entrypoint(
-    module_dir: Path, project_dir: Path
-) -> tuple[Path, str] | None:
+def _find_app_via_entrypoint(module_dir: Path, project_dir: Path) -> tuple[Path, str] | None:
     """Find FastAPI app by following the CLI entrypoint in pyproject.toml.
 
     If pyproject.toml has a script like `myapp = "myapp.subpkg.__main__:main"`,
@@ -400,7 +410,7 @@ def _find_app_via_entrypoint(
 
     try:
         data = tomlkit.parse(pyproject.read_text("UTF-8"))
-    except Exception:
+    except (OSError, ValueError):
         return None
 
     scripts = data.get("project", {}).get("scripts", {})
@@ -410,7 +420,7 @@ def _find_app_via_entrypoint(
     module_name = module_dir.name
 
     # Find script entries that reference this module
-    for script_name, entry in scripts.items():
+    for entry in scripts.values():
         if not isinstance(entry, str):
             continue
         # Parse entry like "module.subpkg.__main__:main"
@@ -468,7 +478,7 @@ def _add_devmode_to_main(content: str) -> str:
     insert_idx = 0
     for i, line in enumerate(lines):
         stripped = line.strip()
-        if stripped.startswith("import ") or stripped.startswith("from "):
+        if stripped.startswith(("import ", "from ")):
             insert_idx = i + 1
         elif stripped and not stripped.startswith("#"):
             break
@@ -501,7 +511,7 @@ def _find_existing_cli_module_path(project_dir: Path, module_name: str) -> str |
 
     try:
         data = tomlkit.parse(pyproject.read_text("UTF-8"))
-    except Exception:
+    except (OSError, ValueError):
         return None
 
     scripts = data.get("project", {}).get("scripts", {})
@@ -509,12 +519,11 @@ def _find_existing_cli_module_path(project_dir: Path, module_name: str) -> str |
         return None
 
     # Look for any script that references our module
-    for script_name, entry in scripts.items():
-        if isinstance(entry, str) and entry.startswith(f"{module_name}."):
+    for entry in scripts.values():
+        if isinstance(entry, str) and entry.startswith(f"{module_name}.") and ":" in entry:
             # Extract module path from "module.subpkg.__main__:main"
-            if ":" in entry:
-                module_path, _ = entry.rsplit(":", 1)
-                return module_path
+            module_path, _ = entry.rsplit(":", 1)
+            return module_path
 
     return None
 
@@ -528,7 +537,7 @@ def _follow_init_reexport(init_file: Path, subpkg_dir: Path) -> tuple[Path, str]
     """
     try:
         content = init_file.read_text("UTF-8")
-    except Exception:
+    except OSError:
         return None
 
     # Look for: from .module import app (or similar variable names)
@@ -562,7 +571,7 @@ def _find_app_in_file(path: Path) -> str | None:
     """Find FastAPI app variable name in a file."""
     try:
         content = path.read_text("UTF-8")
-    except Exception:
+    except OSError:
         return None
 
     # Look for FastAPI() instantiation patterns
@@ -574,17 +583,15 @@ def _find_app_in_file(path: Path) -> str | None:
     return None
 
 
-def render_template(template: str, **kwargs) -> str:
-    """Simple template rendering replacing KEY with value."""
+def render_template(template: str, **kwargs: str) -> str:
+    """Render a template, replacing KEY with value."""
     result = template
     for key, value in kwargs.items():
         result = result.replace(key, value)
     return result
 
 
-def patch_app_file(
-    path: Path, main_module_path: str, app_var: str, dry: bool = False
-) -> bool:
+def patch_app_file(path: Path, main_module_path: str, app_var: str, *, dry: bool = False) -> bool:
     """Patch an existing app.py with frontend integration.
 
     Inserts imports at top (ruff will sort them), route at bottom,
@@ -628,9 +635,7 @@ def patch_app_file(
             content = content.rstrip("\n") + "\n" + import_text
         else:
             # Insert at the found position
-            content = (
-                "".join(lines[:insert_idx]) + import_text + "".join(lines[insert_idx:])
-            )
+            content = "".join(lines[:insert_idx]) + import_text + "".join(lines[insert_idx:])
 
     # Insert FRONTEND_BLOCK after last import (only if Frontend wasn't already there)
     if not has_frontend:
@@ -638,7 +643,7 @@ def patch_app_file(
         last_import_idx = 0
         for i, line in enumerate(lines):
             stripped = line.strip()
-            if stripped.startswith("import ") or stripped.startswith("from "):
+            if stripped.startswith(("import ", "from ")):
                 last_import_idx = i
             elif stripped and not stripped.startswith("#") and last_import_idx > 0:
                 break
@@ -649,9 +654,7 @@ def patch_app_file(
     if route_line not in content:
         lines = content.split("\n")
         lines.append("")
-        lines.append(
-            "# Serve the Vue frontend (needs to be last if SPA catch-all is used)"
-        )
+        lines.append("# Serve the Vue frontend (needs to be last if SPA catch-all is used)")
         lines.append(route_line)
         content = "\n".join(lines)
 
@@ -662,10 +665,7 @@ def patch_app_file(
             args = match.group(2)
             if "debug" not in args:
                 # Add debug=DEVMODE as last argument
-                if args.strip():
-                    new_args = f"{args}, debug=DEVMODE"
-                else:
-                    new_args = "debug=DEVMODE"
+                new_args = f"{args}, debug=DEVMODE" if args.strip() else "debug=DEVMODE"
                 content = (
                     content[: match.start()]
                     + match.group(1)
@@ -701,11 +701,7 @@ def patch_app_file(
             if insert_idx >= len(lines):
                 content = content.rstrip("\n") + "\n" + import_text
             else:
-                content = (
-                    "".join(lines[:insert_idx])
-                    + import_text
-                    + "".join(lines[insert_idx:])
-                )
+                content = "".join(lines[:insert_idx]) + import_text + "".join(lines[insert_idx:])
 
         # Insert lifespan block before the FastAPI() call
         fastapi_line_pattern = r"^(\w+\s*=\s*FastAPI\s*\()"
@@ -723,10 +719,7 @@ def patch_app_file(
         fastapi_match = re.search(fastapi_pattern, content, re.DOTALL)
         if fastapi_match and "lifespan" not in fastapi_match.group(2):
             args = fastapi_match.group(2)
-            if args.strip():
-                new_args = f"{args}, lifespan=lifespan"
-            else:
-                new_args = "lifespan=lifespan"
+            new_args = f"{args}, lifespan=lifespan" if args.strip() else "lifespan=lifespan"
             content = (
                 content[: fastapi_match.start()]
                 + fastapi_match.group(1)
@@ -770,7 +763,7 @@ def patch_app_file(
 
 def patch_vite_config(
     path: Path,
-    module_name: str,
+    *,
     dry: bool = False,
 ) -> bool:
     """Patch an existing vite.config.js/ts by adding fastapi-vue plugin.
@@ -801,15 +794,13 @@ def patch_vite_config(
         # Insert after the last import line before non-import content
         if not import_inserted:
             stripped = line.strip()
-            if stripped.startswith("import ") or stripped.startswith("from "):
-                # Check if next line is not an import
-                if i + 1 < len(lines):
-                    next_stripped = lines[i + 1].strip()
-                    if not next_stripped.startswith(
-                        "import "
-                    ) and not next_stripped.startswith("from "):
-                        new_lines.append(import_line)
-                        import_inserted = True
+            if stripped.startswith(("import ", "from ")) and i + 1 < len(lines):
+                next_stripped = lines[i + 1].strip()
+                if not next_stripped.startswith("import ") and not next_stripped.startswith(
+                    "from "
+                ):
+                    new_lines.append(import_line)
+                    import_inserted = True
 
     if not import_inserted:
         # No imports found, add at top
@@ -842,7 +833,7 @@ def patch_vite_config(
     return True
 
 
-def patch_frontend_health_check(frontend_dir: Path, dry: bool = False) -> bool:
+def patch_frontend_health_check(frontend_dir: Path, *, dry: bool = False) -> bool:
     """Patch Vue app to include FastAPI backend health check.
 
     Tries HelloWorld.vue first (full demo), then falls back to App.vue (minimal).
@@ -884,9 +875,7 @@ def patch_frontend_health_check(frontend_dir: Path, dry: bool = False) -> bool:
     is_typescript = 'lang="ts"' in content
 
     # Build the script content based on JS/TS
-    script_addition = (
-        TS_HEALTH_CHECK_SCRIPT if is_typescript else JS_HEALTH_CHECK_SCRIPT
-    )
+    script_addition = TS_HEALTH_CHECK_SCRIPT if is_typescript else JS_HEALTH_CHECK_SCRIPT
 
     # Insert script addition before </script>
     script_end_match = re.search(r"</script>", content)
@@ -904,9 +893,7 @@ def patch_frontend_health_check(frontend_dir: Path, dry: bool = False) -> bool:
         # Insert before closing </h3>
         h3_close = content.find("    </h3>")
         if h3_close == -1:
-            print(
-                f"⚠️  Skipping {target_file} (no </h3> tag found for status insertion)"
-            )
+            print(f"⚠️  Skipping {target_file} (no </h3> tag found for status insertion)")
             return False
         before, after = content[:h3_close], content[h3_close:]
         content = f"{before}{indent(STATUS_SPAN_TEMPLATE, '  ')}{after}"
@@ -944,12 +931,10 @@ def patch_frontend_health_check(frontend_dir: Path, dry: bool = False) -> bool:
 
 # SHA-256 of old vite-plugin-fastapi.js (before auto-upgrade marker was added)
 # with module name replaced by MODULE_NAME in the outDir path
-_OLD_VITE_PLUGIN_SHA256 = (
-    "93713e879c15a25c750a70ce1de684adeaf11b0c723c38da56e5e7ba207f6632"
-)
+_OLD_VITE_PLUGIN_SHA256 = "93713e879c15a25c750a70ce1de684adeaf11b0c723c38da56e5e7ba207f6632"
 
 
-def _upgrade_old_vite_plugin(path: Path, module_name: str, dry: bool = False) -> None:
+def _upgrade_old_vite_plugin(path: Path, module_name: str, *, dry: bool = False) -> None:
     """Remove old vite-plugin-fastapi.js that lacks auto-upgrade marker.
 
     Old versions didn't have the upgrade marker, so write_file skips them as
@@ -961,7 +946,6 @@ def _upgrade_old_vite_plugin(path: Path, module_name: str, dry: bool = False) ->
     content = path.read_text("UTF-8")
     if UPGRADE_MARKER in content:
         return  # Already new format, write_file handles it
-    import hashlib
 
     normalized = content.replace(
         f"../{module_name}/frontend-build", "../MODULE_NAME/frontend-build"
@@ -983,6 +967,7 @@ _new_files_written: list[tuple[Path, Path]] = []
 def write_file(
     path: Path,
     content: str,
+    *,
     overwrite: bool = True,
     dry: bool = False,
     executable: bool = False,
@@ -1020,7 +1005,7 @@ def write_file(
             if fallback_path is not None:
                 # Write to fallback path instead
                 return _write_fallback_file(
-                    path, fallback_path, content, dry, executable
+                    path, fallback_path, content, dry=dry, executable=executable
                 )
             print(f"ℹ️  Skipping {path} (customized by user)")
             return False
@@ -1043,6 +1028,7 @@ def _write_fallback_file(
     original_path: Path,
     fallback_path: Path,
     content: str,
+    *,
     dry: bool,
     executable: bool,
 ) -> bool:
@@ -1100,8 +1086,6 @@ def merge_pyproject(
     if "requires-python" in data["project"]:
         req = data["project"]["requires-python"]
         # Parse minimum version from strings like ">=3.10" or ">=3.9,<4"
-        import re
-
         match = re.search(r">=\s*(\d+)\.(\d+)", req)
         if match:
             major, minor = int(match.group(1)), int(match.group(2))
@@ -1147,9 +1131,9 @@ def merge_pyproject(
     if "custom" not in hatch_build["targets"]["sdist"]["hooks"]:
         hatch_build["targets"]["sdist"]["hooks"]["custom"] = tomlkit.table()
     if "path" not in hatch_build["targets"]["sdist"]["hooks"]["custom"]:
-        hatch_build["targets"]["sdist"]["hooks"]["custom"]["path"] = hatch_additions[
-            "targets"
-        ]["sdist"]["hooks"]["custom"]["path"]
+        hatch_build["targets"]["sdist"]["hooks"]["custom"]["path"] = hatch_additions["targets"][
+            "sdist"
+        ]["hooks"]["custom"]["path"]
 
     return data
 
@@ -1193,7 +1177,7 @@ def find_js_runtime() -> tuple[str, str] | None:
     return None
 
 
-def ensure_python_project(project_dir: Path, dry: bool = False) -> bool:
+def ensure_python_project(project_dir: Path, *, dry: bool = False) -> bool:
     """Ensure pyproject.toml exists, run uv init if needed."""
     pyproject = project_dir / "pyproject.toml"
     if pyproject.exists():
@@ -1205,7 +1189,7 @@ def ensure_python_project(project_dir: Path, dry: bool = False) -> bool:
 
     print("📦 No pyproject.toml found, initializing Python project...")
     print(">>> uv init")
-    result = subprocess.run(["uv", "init", str(project_dir)], check=False)
+    result = subprocess.run(["uv", "init", str(project_dir)], check=False)  # noqa: S603, S607
     if result.returncode != 0:
         print("❌ uv init failed")
         return False
@@ -1219,7 +1203,7 @@ def ensure_python_project(project_dir: Path, dry: bool = False) -> bool:
     return True
 
 
-def ensure_frontend(project_dir: Path, dry: bool = False) -> bool:
+def ensure_frontend(project_dir: Path, *, dry: bool = False) -> bool:
     """Ensure frontend directory exists with a Vue project, run create-vue if needed."""
     frontend_dir = project_dir / "frontend"
     package_json = frontend_dir / "package.json"
@@ -1251,11 +1235,7 @@ def ensure_frontend(project_dir: Path, dry: bool = False) -> bool:
     print(f">>> {' '.join(create_cmd)}")
     print("(Follow the prompts to configure your Vue app)")
     print()
-    result = subprocess.run(
-        create_cmd,
-        cwd=project_dir,
-        check=False,
-    )
+    result = subprocess.run(create_cmd, cwd=project_dir, check=False)  # noqa: S603
     if result.returncode != 0:
         print("❌ create-vue failed")
         return False
@@ -1277,10 +1257,7 @@ def cmd_setup(args: argparse.Namespace) -> int:
     project_path = Path(args.project_dir)
 
     # Handle both "." and "/path/to/project"
-    if project_path.is_absolute():
-        project_dir = project_path
-    else:
-        project_dir = Path.cwd() / project_path
+    project_dir = project_path if project_path.is_absolute() else Path.cwd() / project_path
 
     project_dir = project_dir.resolve()
     dry = args.dry
@@ -1300,11 +1277,11 @@ def cmd_setup(args: argparse.Namespace) -> int:
     print(f"🔧 Setting up project: {project_dir}")
 
     # Step 1: Ensure frontend exists (do this first so cancellation doesn't leave partial setup)
-    if not ensure_frontend(project_dir, dry):
+    if not ensure_frontend(project_dir, dry=dry):
         return 1
 
     # Step 2: Ensure Python project exists
-    if not ensure_python_project(project_dir, dry):
+    if not ensure_python_project(project_dir, dry=dry):
         return 1
 
     # Detect module name
@@ -1345,9 +1322,7 @@ def cmd_setup(args: argparse.Namespace) -> int:
             default_port, vite_port, dev_port = DEFAULT_PORTS
             ports_note = "(--ports to override)"
 
-    print(
-        f"📡 Ports: default={default_port}, vite={vite_port}, dev={dev_port} {ports_note}"
-    )
+    print(f"📡 Ports: default={default_port}, vite={vite_port}, dev={dev_port} {ports_note}")
 
     # Determine health path configuration
     # Priority: --health argument > existing project value > default
@@ -1374,9 +1349,7 @@ def cmd_setup(args: argparse.Namespace) -> int:
     project_title = module_name.replace("_", " ").title()
 
     # Find existing FastAPI app
-    app_info = (
-        find_fastapi_app(module_dir, project_dir) if module_dir.exists() else None
-    )
+    app_info = find_fastapi_app(module_dir, project_dir) if module_dir.exists() else None
 
     # Template variables
     tpl_vars = {
@@ -1531,7 +1504,7 @@ def cmd_setup(args: argparse.Namespace) -> int:
         # Install the vite plugin file (always update)
         plugin_file = frontend_dir / "vite-plugin-fastapi.js"
         # Upgrade old plugin versions that lack the auto-upgrade marker
-        _upgrade_old_vite_plugin(plugin_file, module_name, dry)
+        _upgrade_old_vite_plugin(plugin_file, module_name, dry=dry)
         template = load_template("frontend/vite-plugin-fastapi.js")
         content = render_template(template, **tpl_vars)
         write_file(plugin_file, content, overwrite=True, dry=dry)
@@ -1541,15 +1514,15 @@ def cmd_setup(args: argparse.Namespace) -> int:
         vite_config_js = frontend_dir / "vite.config.js"
 
         if vite_config_ts.exists():
-            patch_vite_config(vite_config_ts, module_name, dry)
+            patch_vite_config(vite_config_ts, dry=dry)
         elif vite_config_js.exists():
-            patch_vite_config(vite_config_js, module_name, dry)
+            patch_vite_config(vite_config_js, dry=dry)
         else:
             print("⚠️  No vite.config.ts or vite.config.js found in frontend/")
             print("   Run create-vue first to generate a Vite config to patch.")
 
         # Patch Vue app with backend health check
-        patch_frontend_health_check(frontend_dir, dry)
+        patch_frontend_health_check(frontend_dir, dry=dry)
 
     # === Update pyproject.toml ===
     pyproject_path = project_dir / "pyproject.toml"
@@ -1588,9 +1561,7 @@ def cmd_setup(args: argparse.Namespace) -> int:
         else:
             nl = b"\r\n" if b"\r\n" in gitignore_content else b"\n"
             suffix = b"" if gitignore_content.endswith(nl) else nl
-            gitignore_path.write_bytes(
-                gitignore_content + suffix + gitignore_entry.encode() + nl
-            )
+            gitignore_path.write_bytes(gitignore_content + suffix + gitignore_entry.encode() + nl)
             print(f"✅ Added {gitignore_entry} to .gitignore")
     elif dry:
         print(f"✅ Would create .gitignore with {gitignore_entry}")
@@ -1610,12 +1581,12 @@ def cmd_setup(args: argparse.Namespace) -> int:
     print_boxed("Setup complete!")
 
     # Show cd command only if project is not in current directory
-    cd_cmd = "" if project_dir == Path.cwd() else f"cd {project_dir}; "
+    cd_cmd = "" if project_dir == Path.cwd() else f"cd {project_dir} && "
     script_name = module_name.replace("_", "-")
 
-    message = SETUP_COMPLETE_MESSAGE.replace("CD_CMD", cd_cmd).replace(
-        "SCRIPT_NAME", script_name
-    )
+    message = SETUP_COMPLETE_MESSAGE.replace("CD_CMD", cd_cmd).replace("SCRIPT_NAME", script_name)
+    if platform.system() == "Windows":
+        message = message.replace(" && ", "; ")
     print(message)
 
     # Show merge note if any .new.py files were written
@@ -1640,25 +1611,19 @@ def cmd_setup(args: argparse.Namespace) -> int:
 
 def is_uninitialized_folder(path: Path) -> bool:
     """Check if a folder appears to be completely uninitialized."""
-    return (
-        not (path / "pyproject.toml").exists() and not (path / "package.json").exists()
-    )
+    return not (path / "pyproject.toml").exists() and not (path / "package.json").exists()
 
 
 def is_already_patched(path: Path) -> bool:
     """Check if a folder has already been patched by fastapi-vue-setup."""
-    # Check for our scripts directory
-    if (path / "scripts" / "fastapi-vue").exists():
-        return True
-
-    # Check for vite plugin in frontend
-    if (path / "frontend" / "vite-plugin-fastapi.js").exists():
-        return True
-
-    return False
+    # Check for our scripts directory for vite plugin in frontend
+    scriptdir = path / "scripts" / "fastapi-vue"
+    viteplugin = path / "frontend" / "vite-plugin-fastapi.js"
+    return scriptdir.exists() or viteplugin.exists()
 
 
 def main() -> int:
+    """CLI entry point."""
     parser = argparse.ArgumentParser(
         description=f"fastapi-vue-setup {version} - FastAPI + Vue project setup tool",
         formatter_class=argparse.RawDescriptionHelpFormatter,
@@ -1686,11 +1651,9 @@ Examples:
     parser.add_argument(
         "--health",
         metavar="PATH",
-        help="Health check path for devserver (default: /api/health?from=devserver.py, '' to disable)",
-    )
-    parser.add_argument(
-        "--dry", "--dry-run", action="store_true", help="Show what would be done"
+        help='Health check endpoint (disable waiting for backend startup by setting "")',
     )
+    parser.add_argument("--dry", "--dry-run", action="store_true", help="Show what would be done")
 
     args = parser.parse_args()
 
diff --git a/pyproject.toml b/pyproject.toml
index 5902b81..a167c43 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,3 +31,20 @@ dev = ["ruff", "fastapi-vue"]
 
 [tool.uv.sources]
 fastapi-vue = { path = "fastapi-vue", editable = true }
+
+[tool.uv.workspace]
+members = [
+    "f",
+]
+
+[tool.ruff]
+line-length = 100
+
+[tool.ruff.lint]
+select = ["ALL"]
+ignore = ["D203", "D213", "COM812"]  # Conflicting with D211, D212 and formatting
+
+[tool.ruff.lint.per-file-ignores]
+"template/**" = ["F821"]  # Undefined names are template placeholders
+"template/scripts/devserver.py" = ["N806"]  # MODULE_NAME is a template variable
+"fastapi_vue_setup.py" = ["PLR", "C901", "T201", "RUF001"]
diff --git a/scripts/release.py b/scripts/release.py
index ecbbbb5..78b5f14 100755
--- a/scripts/release.py
+++ b/scripts/release.py
@@ -10,25 +10,18 @@ DIST = ROOT / "dist"
 FASTAPI_VUE = ROOT / "fastapi-vue"
 
 
-def main():
+def main() -> None:
+    """Build both packages to dist directory."""
     # Clear the dist directory
     if DIST.exists():
         shutil.rmtree(DIST)
     DIST.mkdir()
 
     # Build fastapi-vue (subdirectory) to root dist
-    subprocess.run(
-        ["uv", "build", "--out-dir", str(DIST)],
-        cwd=FASTAPI_VUE,
-        check=True,
-    )
+    subprocess.run(["uv", "build", "--out-dir", str(DIST)], cwd=FASTAPI_VUE, check=True)  # noqa: S603, S607
 
     # Build fastapi-vue-setup (root)
-    subprocess.run(
-        ["uv", "build", "--out-dir", str(DIST)],
-        cwd=ROOT,
-        check=True,
-    )
+    subprocess.run(["uv", "build", "--out-dir", str(DIST)], cwd=ROOT, check=True)  # noqa: S603, S607
 
 
 if __name__ == "__main__":
diff --git a/template/backend/__init__.py b/template/backend/__init__.py
index e69de29..288b2af 100644
--- a/template/backend/__init__.py
+++ b/template/backend/__init__.py
@@ -0,0 +1 @@
+"""Backend package with FastAPI application and Vue frontend integration."""
diff --git a/template/backend/__main__.py b/template/backend/__main__.py
index 34e26eb..c507a35 100644
--- a/template/backend/__main__.py
+++ b/template/backend/__main__.py
@@ -1,4 +1,6 @@
 # auto-upgrade@fastapi-vue-setup - remove this if you modify this file
+"""Command-line entry point for running the backend server."""
+
 import argparse
 import os
 
@@ -8,7 +10,8 @@ DEFAULT_PORT = TEMPLATE_DEFAULT_PORT
 DEVMODE = os.getenv("ENVPREFIX_DEV") == "1"
 
 
-def main():
+def main() -> None:
+    """Run the backend server with optional arguments."""
     parser = argparse.ArgumentParser(description="Run the MODULE_NAME server.")
     parser.add_argument(
         "-l",
diff --git a/template/backend/app.py b/template/backend/app.py
index 9f8fafb..d5e3e46 100644
--- a/template/backend/app.py
+++ b/template/backend/app.py
@@ -1,3 +1,6 @@
+"""FastAPI application module with Vue frontend integration."""
+
+from collections.abc import AsyncIterator
 from contextlib import asynccontextmanager
 from pathlib import Path
 
@@ -10,7 +13,7 @@ frontend = Frontend(Path(__file__).with_name("frontend-build"))
 
 
 @asynccontextmanager
-async def lifespan(app: FastAPI):
+async def lifespan(_app: FastAPI) -> AsyncIterator[None]:
     """Manage app startup and shutdown resources."""
     await frontend.load()
     yield
@@ -24,7 +27,8 @@ app = FastAPI(title="PROJECT_TITLE", debug=DEVMODE, lifespan=lifespan)
 
 # Health check endpoint for the Vue demo app to verify the backend is running
 @app.get("/api/health")
-async def health_check():
+async def health_check() -> dict[str, str]:
+    """Return backend status for health monitoring."""
     return {"status": "ok"}
 
 
diff --git a/template/scripts/devserver.py b/template/scripts/devserver.py
index 51769f4..b518eb1 100755
--- a/template/scripts/devserver.py
+++ b/template/scripts/devserver.py
@@ -11,7 +11,7 @@ from pathlib import Path
 
 # Import util.py from scripts/fastapi-vue (not a package, so we adjust sys.path)
 sys.path.insert(0, str(Path(__file__).with_name("fastapi-vue")))
-from devutil import (  # type: ignore
+from devutil import (
     ProcessGroup,
     check_ports_free,
     logger,
@@ -26,8 +26,11 @@ HEALTH = TEMPLATE_HEALTH
 
 
 async def run_devserver(
-    listen: str, backend: str, extra_args: list[str] | None = None
+    listen: str,
+    backend: str,
+    extra_args: list[str] | None = None,
 ) -> None:
+    """Start Vite and FastAPI dev servers with hot reload."""
     reporoot = Path(__file__).parent.parent
     front = reporoot / "frontend"
     if not (front / "package.json").exists():
@@ -50,7 +53,8 @@ async def run_devserver(
         await pg.spawn(*vite, cwd=front)
 
 
-def main():
+def main() -> None:
+    """Parse CLI arguments and run the devserver."""
     parser = argparse.ArgumentParser(
         description="Run Vite and FastAPI development servers",
         formatter_class=argparse.RawDescriptionHelpFormatter,
diff --git a/template/scripts/fastapi-vue/build-frontend.py b/template/scripts/fastapi-vue/build-frontend.py
index 152c48c..407e4bf 100644
--- a/template/scripts/fastapi-vue/build-frontend.py
+++ b/template/scripts/fastapi-vue/build-frontend.py
@@ -1,15 +1,19 @@
+# ruff: noqa: INP001
 """Hatch build hook for building Vue frontend during package build."""
 
 import sys
 from pathlib import Path
 
-from hatchling.builders.hooks.plugin.interface import BuildHookInterface  # type: ignore
+from hatchling.builders.hooks.plugin.interface import BuildHookInterface
 
 sys.path.insert(0, str(Path(__file__).parent))
 from buildutil import build
 
 
-class CustomBuildHook(BuildHookInterface):
-    def initialize(self, version, build_data):
+class CustomBuildHook(BuildHookInterface):  # type: ignore[misc]
+    """Hatch build hook that builds Vue frontend during package build."""
+
+    def initialize(self, version: str, build_data: dict) -> None:  # type: ignore[override]
+        """Build frontend before package is built."""
         super().initialize(version, build_data)
         build("frontend")
diff --git a/template/scripts/fastapi-vue/buildutil.py b/template/scripts/fastapi-vue/buildutil.py
index 533c46e..a6fad30 100644
--- a/template/scripts/fastapi-vue/buildutil.py
+++ b/template/scripts/fastapi-vue/buildutil.py
@@ -1,3 +1,4 @@
+# ruff: noqa: INP001
 """Utilities used at build time and in devserver script. No dependencies."""
 
 import logging
@@ -7,6 +8,8 @@ import shutil
 import subprocess
 from pathlib import Path
 
+MIN_NODE_VERSION = 20
+
 
 class _PrefixFormatter(logging.Formatter):
     """Formatter that adds prefix based on log level."""
@@ -30,82 +33,119 @@ def _check_node_version(node_path: str) -> None:
     Raises RuntimeError if version is too old or cannot be determined.
     """
     try:
-        result = subprocess.run(
-            [node_path, "--version"], capture_output=True, text=True, check=True
+        result = subprocess.run(  # noqa: S603
+            [node_path, "--version"],
+            capture_output=True,
+            text=True,
+            check=True,
         )
         version_str = result.stdout.strip()
         # Parse version like "v20.10.0" or "v18.17.1"
         match = re.match(r"v(\d+)", version_str)
         if match:
             major_version = int(match.group(1))
-            if major_version >= 20:
+            if major_version >= MIN_NODE_VERSION:
                 return
-            raise RuntimeError(
-                f"Node.js {version_str} found, but v20+ required (install with nvm)"
-            )
+            msg = f"Node.js {version_str} found, but v{MIN_NODE_VERSION}+ required"
+            raise RuntimeError(msg)
     except (subprocess.CalledProcessError, FileNotFoundError, ValueError):
         pass
-    raise RuntimeError("Could not determine Node.js version")
+    msg = "Could not determine Node.js version"
+    raise RuntimeError(msg)
+
+
+def _validate_npm_runtime(tool: str) -> bool:
+    """Validate npm runtime by checking Node.js version. Returns True if valid."""
+    node_path = shutil.which("node", path=str(Path(tool).parent))
+    if node_path is None:
+        return False
+    try:
+        _check_node_version(node_path)
+    except RuntimeError:
+        return False
+    return True
+
+
+def _find_runtime_from_env(options: list[str]) -> tuple[str, str] | None:
+    """Find runtime specified by JS_RUNTIME environment variable."""
+    js_runtime_env = os.environ.get("JS_RUNTIME")
+    if not js_runtime_env:
+        return None
+
+    js_runtime = js_runtime_env
+    js_path = Path(js_runtime)
+    runtime_name = js_path.name
+
+    # Map node to npm
+    if runtime_name == "node":
+        runtime_name = "npm"
+        js_runtime = str(js_path.parent / "npm") if js_path.parent.name else "npm"
+
+    for option in options:
+        if option != runtime_name and not runtime_name.startswith(option):
+            continue
+
+        tool = shutil.which(js_runtime)
+        if tool is None:
+            msg = f"JS_RUNTIME={js_runtime_env}: {option} not found"
+            raise RuntimeError(msg)
+
+        if option == "npm":
+            node_path = shutil.which("node", path=str(Path(tool).parent))
+            if node_path is None:
+                msg = f"JS_RUNTIME={js_runtime_env}: node not found"
+                raise RuntimeError(msg)
+            _check_node_version(node_path)
+
+        return tool, option
+
+    msg = f"JS_RUNTIME={js_runtime_env} not recognized"
+    raise RuntimeError(msg)
+
+
+def _auto_detect_runtime(options: list[str]) -> tuple[str, str]:
+    """Auto-detect JavaScript runtime from available options."""
+    node_version_error: RuntimeError | None = None
+
+    for option in options:
+        tool = shutil.which(option)
+        if not tool:
+            continue
+
+        if option == "npm" and not _validate_npm_runtime(tool):
+            try:
+                node_path = shutil.which("node", path=str(Path(tool).parent))
+                if node_path:
+                    _check_node_version(node_path)
+            except RuntimeError as e:
+                node_version_error = e
+            continue
+
+        return tool, option
+
+    if node_version_error:
+        raise node_version_error
+    msg = "Node.js (v20+), Deno or Bun is required but none was found"
+    raise RuntimeError(msg)
 
 
 def find_js_runtime() -> tuple[str, str]:
     """Find a JavaScript runtime from JS_RUNTIME env or auto-detect.
 
     Returns (tool_path, tool_name) where tool_name is "deno", "npm", or "bun".
-    Raises JSRuntimeError if no suitable runtime is found.
+    Raises RuntimeError if no suitable runtime is found.
     """
     options = ["npm", "deno", "bun"]
-    node_version_error: RuntimeError | None = None
 
     # Check for JS_RUNTIME environment variable
-    if js_runtime_env := os.environ.get("JS_RUNTIME"):
-        js_runtime = js_runtime_env
-        js_path = Path(js_runtime)
-        runtime_name = js_path.name
-        # Map node to npm
-        if runtime_name == "node":
-            runtime_name = "npm"
-            js_runtime = str(js_path.parent / "npm") if js_path.parent.name else "npm"
-        for option in options:
-            if option == runtime_name or runtime_name.startswith(option):
-                tool = shutil.which(js_runtime)
-                if tool is None:
-                    raise RuntimeError(
-                        f"JS_RUNTIME={js_runtime_env}: {option} not found"
-                    )
-                # Check Node.js version if using npm
-                if option == "npm":
-                    node_path = shutil.which("node", path=str(Path(tool).parent))
-                    if node_path is None:
-                        raise RuntimeError(
-                            f"JS_RUNTIME={js_runtime_env}: node not found"
-                        )
-                    _check_node_version(node_path)  # Raises on failure
-                return tool, option
-        raise RuntimeError(f"JS_RUNTIME={js_runtime_env} not recognized")
+    if result := _find_runtime_from_env(options):
+        return result
 
     # Auto-detect
-    for option in options:
-        if tool := shutil.which(option):
-            # Check Node.js version if using npm
-            if option == "npm":
-                node_path = shutil.which("node", path=str(Path(tool).parent))
-                if node_path is None:
-                    continue
-                try:
-                    _check_node_version(node_path)
-                except RuntimeError as e:
-                    node_version_error = e
-                    continue  # Try next runtime
-            return tool, option
-
-    # No runtime found - provide helpful error
-    if node_version_error:
-        raise node_version_error
-    raise RuntimeError("Node.js (v20+), Deno or Bun is required but none was found")
+    return _auto_detect_runtime(options)
 
 
-def find_build_tool():
+def find_build_tool() -> tuple[list[str], list[str]]:
     """Find JavaScript runtime and construct install/build commands.
 
     Returns (install_cmd, build_cmd) tuples of command lists.
@@ -143,7 +183,7 @@ def find_dev_tool() -> list[str]:
 
     if name == "bun":
         logger.warning(
-            "Bun has a bug in WS proxying (https://github.com/oven-sh/bun/issues/9882). Consider using npm instead."
+            "Bun has a WS proxy bug (github.com/oven-sh/bun/issues/9882). Consider npm.",
         )
 
     return [tool, *dev_args[name]]
@@ -176,16 +216,16 @@ def build(folder: str = "frontend") -> None:
         install_cmd, build_cmd = find_build_tool()
     except RuntimeError as e:
         logger.warning(e)
-        raise SystemExit(1)
+        raise SystemExit(1) from None
 
-    def run(cmd):
+    def run(cmd: list[str]) -> None:
         display_cmd = [Path(cmd[0]).stem, *cmd[1:]]
         logger.info("### %s", " ".join(display_cmd))
-        subprocess.run(cmd, check=True, cwd=folder)
+        subprocess.run(cmd, check=True, cwd=folder)  # noqa: S603
 
     try:
         run(install_cmd)
         logger.info("")
         run(build_cmd)
     except subprocess.CalledProcessError:
-        raise SystemExit(1)
+        raise SystemExit(1) from None
diff --git a/template/scripts/fastapi-vue/devutil.py b/template/scripts/fastapi-vue/devutil.py
index f4cf749..d691801 100644
--- a/template/scripts/fastapi-vue/devutil.py
+++ b/template/scripts/fastapi-vue/devutil.py
@@ -1,27 +1,33 @@
+# ruff: noqa: INP001
 """Utilities meant for devserver script, used only in source repository with dev deps."""
 
 import asyncio
 import subprocess
 import sys
-from collections.abc import Coroutine
 from contextlib import suppress
 from pathlib import Path
-from typing import Any
+from typing import TYPE_CHECKING, Any, Self
 
 import httpx
 from buildutil import find_dev_tool, find_install_tool, logger
 from fastapi_vue.hostutil import parse_endpoint
 
+if TYPE_CHECKING:
+    from collections.abc import Coroutine
+
 
 class ProcessGroup:
     """Manage async subprocesses with automatic cleanup, like TaskGroup for processes."""
 
-    def __init__(self):
+    def __init__(self) -> None:
+        """Initialize empty process tracking."""
         self._procs: list[asyncio.subprocess.Process] = []
         self._cmds: dict[int, str] = {}  # pid -> command name
 
     async def spawn(
-        self, *cmd: str, cwd: str | None = None
+        self,
+        *cmd: str,
+        cwd: str | None = None,
     ) -> asyncio.subprocess.Process:
         """Spawn a subprocess and track it."""
         cmd_name = Path(cmd[0]).stem
@@ -32,7 +38,8 @@ class ProcessGroup:
         return proc
 
     async def wait(
-        self, *waitables: "asyncio.subprocess.Process | Coroutine[Any, Any, Any]"
+        self,
+        *waitables: "asyncio.subprocess.Process | Coroutine[Any, Any, Any]",
     ) -> None:
         """Wait for processes/coroutines to complete, raise SystemExit on failure."""
 
@@ -43,8 +50,7 @@ class ProcessGroup:
                 raise subprocess.CalledProcessError(returncode, cmd_name)
 
         tasks = [
-            wait_proc(w) if isinstance(w, asyncio.subprocess.Process) else w
-            for w in waitables
+            wait_proc(w) if isinstance(w, asyncio.subprocess.Process) else w for w in waitables
         ]
         try:
             await asyncio.gather(*tasks)
@@ -52,14 +58,15 @@ class ProcessGroup:
             logger.warning("%s failed with exit status %d", e.cmd, e.returncode)
             raise SystemExit(1) from None
 
-    async def __aenter__(self):
+    async def __aenter__(self) -> Self:
+        """Enter the async context manager."""
         return self
 
-    async def __aexit__(self, exc_type, *_):
+    async def __aexit__(self, exc_type: type[BaseException] | None, *_: object) -> None:
         """Wait for one process to exit, terminate others, then wait for all."""
         await self._cleanup(immediate=exc_type is not None)
 
-    async def _cleanup(self, immediate: bool = False):
+    async def _cleanup(self, *, immediate: bool = False) -> None:
         running = [p for p in self._procs if p.returncode is None]
         if not running:
             return
@@ -87,7 +94,7 @@ class ProcessGroup:
                         asyncio.wait_for(
                             asyncio.gather(*[p.wait() for p in still_running]),
                             timeout=10,
-                        )
+                        ),
                     )
                 except TimeoutError:
                     for p in self._procs:
@@ -111,7 +118,7 @@ async def check_ports_free(*urls: str) -> None:
         await asyncio.gather(*[check(client, url) for url in urls])
 
 
-async def ready(url: str, path: str = "", max_attempts=50) -> None:
+async def ready(url: str, path: str = "", max_attempts: int = 50) -> None:
     """Wait for the server to be ready by polling an endpoint.
 
     Use empty path to disable the check and make this return immediately.
@@ -124,17 +131,19 @@ async def ready(url: str, path: str = "", max_attempts=50) -> None:
         for attempt in range(max_attempts):
             try:
                 await client.get(f"{url}{path}", timeout=1.0)
-                logger.info("✓ Backend ready!")
-                return
             except httpx.RequestError:
                 if attempt == max_attempts - 1:
                     logger.warning("Backend didn't start in time")
-                    raise SystemExit(1)
+                    raise SystemExit(1) from None
                 await asyncio.sleep(0.1)
+            else:
+                logger.info("✓ Backend ready!")
+                return
 
 
 def setup_vite(
-    endpoint: str, default_port: int = 5173
+    endpoint: str,
+    default_port: int = 5173,
 ) -> tuple[str, list[str], list[str]]:
     """Parse frontend endpoint and build commands.
 
@@ -160,7 +169,9 @@ def setup_vite(
 
 
 def setup_fastapi(
-    endpoint: str, module: str, default_port: int = 8000
+    endpoint: str,
+    module: str,
+    default_port: int = 8000,
 ) -> tuple[str, list[str]]:
     """Parse backend endpoint and build uvicorn command.
 
@@ -175,7 +186,7 @@ def setup_fastapi(
 
     host = endpoints[0]["host"]
     port = endpoints[0]["port"]
-    reload_dir = module.split(".")[0]  # Don't reload on frontend changes
+    reload_dir = module.split(".", maxsplit=1)[0]  # Don't reload on frontend changes
 
     cmd = [
         sys.executable,
@@ -192,7 +203,9 @@ def setup_fastapi(
 
 
 def setup_cli(
-    cli: str, endpoint: str, default_port: int = 8000
+    cli: str,
+    endpoint: str,
+    default_port: int = 8000,
 ) -> tuple[str, list[str]]:
     """Parse backend endpoint and build CLI command.