# -*- coding: utf-8 -*-
"""mcpgateway CLI ─ a thin wrapper around Uvicorn
Copyright 2025
SPDX-License-Identifier: Apache-2.0
Authors: Mihai Criveti
This module is exposed as a **console-script** via:
[project.scripts]
mcpgateway = "mcpgateway.cli:main"
so that a user can simply type `mcpgateway ...` instead of the longer
`uvicorn mcpgateway.main:app ...`.
Features
─────────
* Injects the default FastAPI application path (``mcpgateway.main:app``)
when the user doesn't supply one explicitly.
* Adds sensible default host/port (127.0.0.1:4444) unless the user passes
``--host``/``--port`` or overrides them via the environment variables
``MCG_HOST`` and ``MCG_PORT``.
* Forwards *all* remaining arguments verbatim to Uvicorn's own CLI, so
`--reload`, `--workers`, etc. work exactly the same.
Typical usage
─────────────
```console
$ mcpgateway --reload # dev server on 127.0.0.1:4444
$ mcpgateway --workers 4 # production-style multiprocess
$ mcpgateway 127.0.0.1:8000 --reload # explicit host/port keeps defaults out
$ mcpgateway mypkg.other:app # run a different ASGI callable
```
"""
# Future
from __future__ import annotations
# Standard
import os
import sys
from typing import List
# Third-Party
import uvicorn
# First-Party
from mcpgateway import __version__
# ---------------------------------------------------------------------------
# Configuration defaults (overridable via environment variables)
# ---------------------------------------------------------------------------
DEFAULT_APP = "mcpgateway.main:app" # dotted path to FastAPI instance
DEFAULT_HOST = os.getenv("MCG_HOST", "127.0.0.1")
DEFAULT_PORT = int(os.getenv("MCG_PORT", "4444"))
# ---------------------------------------------------------------------------
# Helper utilities
# ---------------------------------------------------------------------------
def _needs_app(arg_list: List[str]) -> bool:
"""Return *True* when the CLI invocation has *no* positional APP path.
According to Uvicorn's argument grammar, the **first** non-flag token
is taken as the application path. We therefore look at the first
element of *arg_list* (if any) - if it *starts* with a dash it must be
an option, hence the app path is missing and we should inject ours.
Args:
arg_list (List[str]): List of arguments
Returns:
bool: Returns *True* when the CLI invocation has *no* positional APP path
"""
return len(arg_list) == 0 or arg_list[0].startswith("-")
def _insert_defaults(raw_args: List[str]) -> List[str]:
"""Return a *new* argv with defaults sprinkled in where needed.
Args:
raw_args (List[str]): List of input arguments to cli
Returns:
List[str]: List of arguments
"""
args = list(raw_args) # shallow copy - we'll mutate this
# 1️⃣ Ensure an application path is present.
if _needs_app(args):
args.insert(0, DEFAULT_APP)
# 2️⃣ Supply host/port if neither supplied nor UNIX domain socket.
if "--uds" not in args:
if "--host" not in args and "--http" not in args:
args.extend(["--host", DEFAULT_HOST])
if "--port" not in args:
args.extend(["--port", str(DEFAULT_PORT)])
return args
# ---------------------------------------------------------------------------
# Public entry-point
# ---------------------------------------------------------------------------
def main() -> None: # noqa: D401 - imperative mood is fine here
"""Entry point for the *mcpgateway* console script (delegates to Uvicorn)."""
# Check for version flag
if "--version" in sys.argv or "-V" in sys.argv:
print(f"mcpgateway {__version__}")
return
# Discard the program name and inspect the rest.
user_args = sys.argv[1:]
uvicorn_argv = _insert_defaults(user_args)
# Uvicorn's `main()` uses sys.argv - patch it in and run.
sys.argv = ["mcpgateway", *uvicorn_argv]
uvicorn.main() # pylint: disable=no-value-for-parameter
if __name__ == "__main__": # pragma: no cover - executed only when run directly
main()
