Make devserver backend health check endpoint configurable, preserved in upgrades and optional.

fastapi-vue/fastapi_vue/hostutil.py

@@ -12,6 +12,7 @@ def parse_endpoint(value: str | None, default_port: int = 0) -> list[dict]:
 
     Returns:
         List of dicts with uvicorn bind kwargs (host/port or uds).
+        Two entries may be returned for IPv4 and IPv6 (all interaces).
 
     Supported forms:
     - None or empty -> [{host: "localhost", port: default_port}]
@@ -65,3 +66,19 @@ def parse_endpoint(value: str | None, default_port: int = 0) -> list[dict]:
         ipaddress.ip_address(host)
 
     return [{"host": host, "port": port}]
+
+
+def parse_endpoints(
+    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}"]
+    elif isinstance(listen, str):
+        listen = [listen]
+    return [ep for s in listen for ep in parse_endpoint(s, default_port)]

fastapi-vue/fastapi_vue/server.py

@@ -6,7 +6,7 @@ from contextlib import suppress
 import uvicorn
 from uvicorn import Config, Server
 
-from .hostutil import parse_endpoint
+from .hostutil import parse_endpoints
 
 logger = logging.getLogger(__name__)
 
@@ -30,13 +30,9 @@ def run(
         workers: Number of worker processes (requires uvicorn.run, single endpoint only).
         **uvicorn_config: Additional uvicorn config options (overrides all other settings).
     """
-    if listen is None:
+    endpoints = parse_endpoints(listen, default_port)
-        listen = [f"localhost:{default_port}"]
+    if not endpoints:
-    elif isinstance(listen, str):
+        raise ValueError("No endpoints to serve; check listen configuration")
-        listen = [listen]
-    endpoints: list[dict] = []
-    for ep in listen:
-        endpoints.extend(parse_endpoint(ep, default_port))
 
     conf: dict[str, object] = {"app": app, "reload": reload, "workers": workers}
     proxy = os.getenv("FORWARDED_ALLOW_IPS", "127.0.0.1,::1")
@@ -45,7 +41,7 @@ def run(
         conf["forwarded_allow_ips"] = proxy
     conf.update(uvicorn_config)
 
-    with suppress(KeyboardInterrupt):
+    with suppress(KeyboardInterrupt, asyncio.CancelledError):
         if reload or workers:
             serve_multiprocess(endpoints, **conf)
         else:

fastapi-vue/fastapi_vue/staticfiles.py

@@ -276,6 +276,6 @@ def _devmode_respond(request: Request, name=""):
     return JSONResponse(
         status_code=409,
         content={
-            "detail": "Frontend assets served by Vite in debug mode. You are on backend, connect to frontend instead."
+            "detail": "[devmode] Not serving frontend files here. Should you connect to Vite instead?"
         },
     )

fastapi_vue_setup.py

@@ -21,6 +21,7 @@ import subprocess
 import sys
 from pathlib import Path
 from textwrap import indent
+from typing import Literal
 
 import tomlkit
 
@@ -38,22 +39,39 @@ def print_boxed(text: str) -> None:
     print(f"╰{'─' * width}╯")
 
 
-def ruff_format_content(content: str, target_path: Path) -> str:
+def ruff_format_content(
+    content: str, target_path: Path, *, mode: Literal["isort", "full"] = "full"
+) -> str:
     """Format Python content using ruff with project settings.
 
-    Writes to a temp file (.new.py) next to target, runs ruff check (import sorting)
+    Writes to a temp file next to target, runs ruff check (import sorting)
-    and ruff format on it, reads back the result, and cleans up.
+    and optionally ruff format on it, reads back the result, and cleans up.
     Returns the formatted content, or original if ruff fails.
+
+    mode='isort' only sorts imports; mode='full' also formats.
     """
     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", "ruff", "check", "--select", "I", "--fix", str(temp_file)],
+            [
+                "uv",
+                "run",
+                "--with",
+                "ruff",
+                "ruff",
+                "check",
+                "--select",
+                "I",
+                "--fix",
+                str(temp_file),
+            ],
             cwd=target_path.parent,
             capture_output=True,
         )
+        if mode == "isort":
+            return temp_file.read_text("UTF-8")
         # Then format
         result = subprocess.run(
             ["uv", "run", "--with", "ruff", "ruff", "format", str(temp_file)],
@@ -92,6 +110,9 @@ def uv_add_packages(
 # If vite == dev, dev is incremented by 100
 DEFAULT_PORTS = (3100, 3100, 3200)
 
+# Default health check path for devserver backend readiness check
+DEFAULT_HEALTH = "/api/health?from=devserver.py"
+
 # Marker comment indicating file can be auto-upgraded
 # Users should remove this line to prevent automatic updates
 UPGRADE_MARKER = "auto-upgrade@fastapi-vue-setup"
@@ -242,23 +263,20 @@ def find_import_insertion_line(source: str) -> int:
     return 2 if source.startswith("#!") else 1
 
 
-def extract_existing_ports(project_dir: 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.
     """
-    module_name = find_module_name(project_dir)
-    if not module_name:
-        return None
-
     default_port = None
     vite_port = None
     dev_port = None
 
-    # Try to extract DEFAULT_PORT from __main__.py
+    # Try to extract DEFAULT_PORT from the CLI main module
-    main_file = project_dir / module_name / "__main__.py"
+    if main.exists():
-    if main_file.exists():
+        content = main.read_text("UTF-8")
-        content = main_file.read_text("UTF-8")
         match = re.search(r"DEFAULT_PORT\s*=\s*(\d+)", content)
         if match:
             default_port = int(match.group(1))
@@ -285,6 +303,29 @@ def extract_existing_ports(project_dir: Path) -> tuple[int, int, int] | None:
     return None
 
 
+# Sentinel for "not found" in extract_existing_health
+_HEALTH_NOT_FOUND = object()
+
+
+def extract_existing_health(project_dir: Path) -> str | object:
+    """Extract existing health path configuration from devserver.py.
+
+    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():
+        return _HEALTH_NOT_FOUND
+
+    content = devserver_file.read_text("UTF-8")
+    # Match HEALTH = "/path" or HEALTH = ""
+    match = re.search(r'^HEALTH\s*=\s*"([^"]*)"', content, re.MULTILINE)
+    if match:
+        return match.group(1)
+    return _HEALTH_NOT_FOUND
+
+
 def load_template(path: str) -> str:
     """Load a template file from the template directory."""
     return (TEMPLATE_DIR / path).read_text("UTF-8")
@@ -416,10 +457,43 @@ def _find_app_in_subpackage(subpkg_dir: Path) -> tuple[Path, str] | None:
     return None
 
 
-def _find_existing_cli_entrypoint(project_dir: Path, module_name: str) -> str | None:
+def _add_devmode_to_main(content: str) -> str:
+    """Add DEVMODE variable to an existing main module."""
+    lines = content.splitlines()
+
+    # Check if os is imported
+    has_os_import = any("import os" in line for line in lines)
+
+    # Find the first import line
+    insert_idx = 0
+    for i, line in enumerate(lines):
+        stripped = line.strip()
+        if stripped.startswith("import ") or stripped.startswith("from "):
+            insert_idx = i + 1
+        elif stripped and not stripped.startswith("#"):
+            break
+
+    # Insert imports and DEVMODE after existing imports
+    new_lines = []
+    if not has_os_import:
+        new_lines.append("import os")
+    new_lines.extend(
+        [
+            "",
+            "# Added by fastapi-vue-setup",
+            'DEVMODE = os.getenv("ENVPREFIX_DEV") == "1"',
+            "",
+        ]
+    )
+
+    lines[insert_idx:insert_idx] = new_lines
+    return "\n".join(lines)
+
+
+def _find_existing_cli_module_path(project_dir: Path, module_name: str) -> str | None:
     """Check if pyproject.toml already has a CLI entrypoint for this module.
 
-    Returns the entrypoint string if found, None otherwise.
+    Returns the module path (e.g., 'module.subpkg.__main__') if found, None otherwise.
     """
     pyproject = project_dir / "pyproject.toml"
     if not pyproject.exists():
@@ -437,7 +511,10 @@ def _find_existing_cli_entrypoint(project_dir: Path, module_name: str) -> str |
     # 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}."):
-            return f'{script_name} = "{entry}"'
+            # Extract module path from "module.subpkg.__main__:main"
+            if ":" in entry:
+                module_path, _ = entry.rsplit(":", 1)
+                return module_path
 
     return None
 
@@ -506,7 +583,7 @@ def render_template(template: str, **kwargs) -> str:
 
 
 def patch_app_file(
-    path: Path, module_name: str, app_var: str, dry: bool = False
+    path: Path, main_module_path: str, app_var: str, dry: bool = False
 ) -> bool:
     """Patch an existing app.py with frontend integration.
 
@@ -524,7 +601,7 @@ def patch_app_file(
 
     # Check what's already patched
     has_frontend = "from fastapi_vue import Frontend" in content
-    has_devmode = f"from {module_name}.__main__ import DEVMODE" in content
+    has_devmode = f"from {main_module_path} import DEVMODE" in content
     has_debug_arg = re.search(r"FastAPI\s*\([^)]*debug\s*=", content) is not None
     has_lifespan = "await frontend.load()" in content
 
@@ -539,7 +616,7 @@ def patch_app_file(
     if not has_frontend:
         imports.extend(["from pathlib import Path", "from fastapi_vue import Frontend"])
     if not has_devmode:
-        imports.append(f"from {module_name}.__main__ import DEVMODE")
+        imports.append(f"from {main_module_path} import DEVMODE")
     if imports:
         insert_line = find_import_insertion_line(content)
         lines = content.splitlines(keepends=True)
@@ -668,6 +745,8 @@ def patch_app_file(
         print(f"✅ Would patch {path}")
         return True
 
+    # Sort imports only (avoid full formatting of user code)
+    content = ruff_format_content(content, path, mode="isort")
     path.write_text(content, "UTF-8", newline="\n")
     print(f"✅ Patched {path}")
 
@@ -789,7 +868,7 @@ def patch_frontend_health_check(frontend_dir: Path, dry: bool = False) -> bool:
             target_file = app_vue
 
     if target_file is None:
-        print("ℹ️  No Vue file found to patch, skipping frontend health check")
+        print("ℹ️  No default App.vue found to patch, not adding /api/health check")
         return False
 
     original_content = target_file.read_text("UTF-8")
@@ -834,7 +913,7 @@ def patch_frontend_health_check(frontend_dir: Path, dry: bool = False) -> bool:
     else:
         # Minimal App.vue - only patch if it contains the default welcome message
         if "<h1>You did it!</h1>" not in content:
-            print(f"ℹ️  Skipping {target_file} (not a default Vue template)")
+            print(f"ℹ️  Skipping {target_file} (not a Vue demo app)")
             return False
         # Insert before the </p> tag
         template_end = content.find("</template>")
@@ -976,6 +1055,7 @@ def _write_fallback_file(
         existing_content = fallback_path.read_text("UTF-8")
         if existing_content == content:
             print(f"✔️  {fallback_path} (already up to date)")
+            _new_files_written.append((fallback_path, original_path))
             return False
 
     if dry:
@@ -1236,13 +1316,28 @@ def cmd_setup(args: argparse.Namespace) -> int:
     else:
         print(f"📦 Module: {module_name}")
 
+    module_dir = project_dir / module_name
+    scripts_dir = project_dir / "scripts"
+    fastapi_vue_scripts = scripts_dir / "fastapi-vue"
+
+    # Check if project already has a CLI entrypoint in pyproject.toml
+    existing_cli_module = _find_existing_cli_module_path(project_dir, module_name)
+
+    # Determine main module path for DEVMODE import
+    main_module_path = existing_cli_module or f"{module_name}.__main__"
+    if existing_cli_module:
+        print(f"ℹ️  Using existing CLI: {existing_cli_module}")
+
+    # Resolve the CLI main module to a file path
+    main = project_dir / Path(*main_module_path.split(".")).with_suffix(".py")
+
     # Determine port configuration
     # Priority: --ports argument > existing project values > defaults
     if args.ports:
         default_port, vite_port, dev_port = parse_ports(args.ports)
         ports_note = "(--ports)"
     else:
-        existing_ports = extract_existing_ports(project_dir)
+        existing_ports = extract_existing_ports(project_dir, main)
         if existing_ports:
             default_port, vite_port, dev_port = existing_ports
             ports_note = "(kept for upgrade)"
@@ -1254,9 +1349,35 @@ def cmd_setup(args: argparse.Namespace) -> int:
         f"📡 Ports: default={default_port}, vite={vite_port}, dev={dev_port} {ports_note}"
     )
 
+    # Determine health path configuration
+    # Priority: --health argument > existing project value > default
+    if args.health is not None:
+        health = args.health
+        health_note = "(--health)" if health else "(disabled via --health)"
+    else:
+        existing_health = extract_existing_health(project_dir)
+        if existing_health is not _HEALTH_NOT_FOUND:
+            # Explicitly configured (path string, possibly empty to disable)
+            health = existing_health
+            health_note = "(kept for upgrade)"
+        else:
+            # Not found - use default
+            health = DEFAULT_HEALTH
+            health_note = "(--health to override)"
+
+    if health:
+        print(f"🏥 Health check: {health} {health_note}")
+    else:
+        print(f"🏥 Health check: disabled {health_note}")
+
     # Title for templates
     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
+    )
+
     # Template variables
     tpl_vars = {
         "MODULE_NAME": module_name,
@@ -1264,30 +1385,25 @@ def cmd_setup(args: argparse.Namespace) -> int:
         "TEMPLATE_DEFAULT_PORT": str(default_port),
         "TEMPLATE_VITE_PORT": str(vite_port),
         "TEMPLATE_DEV_PORT": str(dev_port),
+        "TEMPLATE_HEALTH": f'"{health}"',
         "ENVPREFIX": module_name.upper(),
         "PROJECT_CLI": module_name,
+        "MAIN_MODULE": main_module_path,
     }
 
-    module_dir = project_dir / module_name
-    scripts_dir = project_dir / "scripts"
-    fastapi_vue_scripts = scripts_dir / "fastapi-vue"
-
-    # Find existing FastAPI app
-    app_info = (
-        find_fastapi_app(module_dir, project_dir) if module_dir.exists() else None
-    )
-
     if app_info:
         app_file, app_var = app_info
         print(f"📍 Found FastAPI app: {app_var} in {app_file.name}")
         tpl_vars["APP_VAR"] = app_var
-        tpl_vars["APP_MODULE"] = app_file.stem
+        # Dotted module path relative to project dir (e.g. "paskia.fastapi.mainapp")
+        app_module = ".".join(app_file.relative_to(project_dir).with_suffix("").parts)
+        tpl_vars["APP_MODULE"] = app_module
     else:
         print("📍 No existing FastAPI app found, will create new one")
         app_file = None
         app_var = "app"
         tpl_vars["APP_VAR"] = app_var
-        tpl_vars["APP_MODULE"] = "app"
+        tpl_vars["APP_MODULE"] = f"{module_name}.app"
 
     # Create directories
     if not dry:
@@ -1340,7 +1456,7 @@ def cmd_setup(args: argparse.Namespace) -> int:
     # === Handle app module ===
     if app_file:
         # Existing app: patch with import, route, and try to patch lifespan
-        patch_app_file(app_file, module_name, app_var, dry=dry)
+        patch_app_file(app_file, main_module_path, app_var, dry=dry)
     else:
         # No app: create full app.py
         # Create __init__.py if missing
@@ -1357,14 +1473,16 @@ def cmd_setup(args: argparse.Namespace) -> int:
         write_file(app_file_path, content, overwrite=False, dry=dry)
 
     # === Handle __main__.py ===
-    main_file = module_dir / "__main__.py"
+    if existing_cli_module:
+        # Existing CLI entrypoint - write .new.py beside the existing main module
+        main_fallback = main.with_suffix(".new.py")
+    else:
         main_fallback = module_dir / "__main__.new.py"
+
+    main_file = module_dir / "__main__.py"
     template = load_template("backend/__main__.py")
     main_content = render_template(template, **tpl_vars)
 
-    # Check if project already has a CLI entrypoint in pyproject.toml
-    existing_cli = _find_existing_cli_entrypoint(project_dir, module_name)
-
     if main_file.exists():
         # File exists: update if it has the auto-upgrade marker, otherwise use fallback
         write_file(
@@ -1374,7 +1492,7 @@ def cmd_setup(args: argparse.Namespace) -> int:
             dry=dry,
             fallback_path=main_fallback,
         )
-    elif not existing_cli:
+    elif not existing_cli_module:
         # No file and no existing entrypoint: create new __main__.py
         write_file(
             main_file,
@@ -1383,8 +1501,29 @@ def cmd_setup(args: argparse.Namespace) -> int:
             dry=dry,
         )
     else:
-        # No file but has existing entrypoint - don't create (user has custom CLI setup)
+        # Existing CLI entrypoint: write our template as .new.py beside the existing module
-        print(f"ℹ️  Skipping __main__.py (package already has CLI: {existing_cli})")
+        # and also patch the existing module with DEVMODE if needed
+        _write_fallback_file(
+            main,
+            main_fallback,
+            main_content,
+            dry=dry,
+            executable=False,
+        )
+        if main.exists():
+            content = main.read_text("UTF-8")
+            if "DEVMODE" not in content:
+                new_content = _add_devmode_to_main(content)
+                new_file = main.with_suffix(".new.py")
+                _write_fallback_file(
+                    main,
+                    new_file,
+                    new_content,
+                    dry=dry,
+                    executable=False,
+                )
+        else:
+            print(f"⚠️  Existing CLI main module {main} not found")
 
     # === Update vite.config.js/ts ===
     frontend_dir = project_dir / "frontend"
@@ -1482,12 +1621,16 @@ def cmd_setup(args: argparse.Namespace) -> int:
     # Show merge note if any .new.py files were written
     if _new_files_written:
         print()
-        print(
+        print("⚠️  Some files could not be auto-upgraded because you customized them.")
-            "⚠️  Note: Some files could not be auto-upgraded because you customized them."
-        )
         print("   Please manually merge the following files:")
         for new_file, original_file in _new_files_written:
-            print(f"     • {new_file.name} → {original_file.name}")
+            try:
+                new_rel = new_file.relative_to(project_dir)
+                orig_rel = original_file.relative_to(project_dir)
+            except ValueError:
+                new_rel = new_file.name
+                orig_rel = original_file.name
+            print(f"     • {new_rel} → {orig_rel}")
         print()
         # Clear the list for potential subsequent runs
         _new_files_written.clear()
@@ -1540,6 +1683,11 @@ Examples:
         metavar="BACKEND,VITE,DEV",
         help="Port configuration as comma-separated values (default: 3100,3100,3200)",
     )
+    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"
     )

template/backend/__main__.py

@@ -5,7 +5,7 @@ import os
 from fastapi_vue import server
 
 DEFAULT_PORT = TEMPLATE_DEFAULT_PORT
-DEVMODE = bool(os.getenv("ENVPREFIX_DEV") == "1")
+DEVMODE = os.getenv("ENVPREFIX_DEV") == "1"
 
 
 def main():
@@ -17,12 +17,12 @@ def main():
         help=(f"Endpoint (default: localhost:{DEFAULT_PORT})."),
     )
     args = parser.parse_args()
-    dev = {"reload": True, "reload_dirs": ["MODULE_NAME"]}
+    dev = {"reload": True, "reload_dirs": ["paskia"]} if DEVMODE else {}
     server.run(
-        "MODULE_NAME.APP_MODULE:APP_VAR",
+        "APP_MODULE:APP_VAR",
         listen=args.listen,
         default_port=DEFAULT_PORT,
-        **(dev if DEVMODE else {}),
+        **dev,
     )
 
 

template/backend/app.py

@@ -3,7 +3,7 @@ from pathlib import Path
 
 from fastapi import FastAPI
 from fastapi_vue import Frontend
-from MODULE_NAME.__main__ import DEVMODE
+from MAIN_MODULE import DEVMODE
 
 # Vue Frontend static files
 frontend = Frontend(Path(__file__).with_name("frontend-build"))

template/frontend/vite-plugin-fastapi.js

@@ -11,7 +11,7 @@
  */
 
 export default function fastapiVue({ paths = ["/api"] } = {}) {
-  const backendUrl = process.env.ENVPREFIX_BACKEND_URL || "http://localhost:TEMPLATE_DEFAULT_PORT"
+  const backendUrl = process.env.ENVPREFIX_BACKEND_URL || "http://localhost:TEMPLATE_DEV_PORT"
 
   // Build proxy configuration for each path
   const proxy = {}

template/scripts/devserver.py

@@ -22,6 +22,7 @@ from devutil import (  # type: ignore
 
 DEFAULT_VITE_PORT = TEMPLATE_VITE_PORT
 DEFAULT_DEV_PORT = TEMPLATE_DEV_PORT
+HEALTH = TEMPLATE_HEALTH
 
 
 async def run_devserver(
@@ -45,7 +46,7 @@ async def run_devserver(
         npm_i = await pg.spawn(*npm_install, cwd=front)
         await check_ports_free(viteurl, backurl)
         await pg.spawn(*MODULE_NAME, *(extra_args or []))
-        await pg.wait(npm_i, ready(backurl, path="/api/health?from=devserver.py"))
+        await pg.wait(npm_i, ready(backurl, path=HEALTH))
         await pg.spawn(*vite, cwd=front)
 
 
@@ -56,13 +57,14 @@ def main():
         epilog=HELP_EPILOG,
     )
     parser.add_argument(
-        "-l", "--listen",
+        "-l",
-        metavar="host:port",
+        "--listen",
+        metavar="addr",
         help=f"Vite (default: localhost:{DEFAULT_VITE_PORT})",
     )
     parser.add_argument(
         "--backend",
-        metavar="host:port",
+        metavar="addr",
         help=f"FastAPI (default: localhost:{DEFAULT_DEV_PORT})",
     )
     args, extra_args = parser.parse_known_args()
@@ -71,7 +73,7 @@ def main():
 
 
 HELP_EPILOG = """
-  scripts/devserver.py [args to PROJECT_CLI]
+  Other options are forwarded to PROJECT_CLI [args]
 
   JS_RUNTIME environment variable can be used to select the JS runtime:
   npm, deno, bun, or full path to the runtime executable (node maps to npm).

template/scripts/fastapi-vue/devutil.py

@@ -111,18 +111,19 @@ 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 = "") -> None:
+async def ready(url: str, path: str = "", max_attempts=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.
     Raises SystemExit(1) if server doesn't start in time.
     """
-    max_attempts = 50
+    if not path:
-    full_url = f"{url}{path}"
+        return
 
     async with httpx.AsyncClient() as client:
         for attempt in range(max_attempts):
             try:
-                await client.get(full_url, timeout=1.0)
+                await client.get(f"{url}{path}", timeout=1.0)
                 logger.info("✓ Backend ready!")
                 return
             except httpx.RequestError: