unity-mcp/Server/src/main.py

from starlette.requests import Request
from transport.unity_instance_middleware import (
    UnityInstanceMiddleware,
    get_unity_instance_middleware
)
from services.api_key_service import ApiKeyService
from transport.legacy.unity_connection import get_unity_connection_pool, UnityConnectionPool
from services.tools import register_all_tools
from core.telemetry import record_milestone, record_telemetry, MilestoneType, RecordType, get_package_version
from services.resources import register_all_resources
from transport.plugin_registry import PluginRegistry
from transport.plugin_hub import PluginHub
from services.custom_tool_service import (
    CustomToolService,
    resolve_project_id_for_unity_instance,
)
from core.config import config
from starlette.routing import WebSocketRoute
from starlette.responses import JSONResponse
import argparse
import asyncio
import logging
from contextlib import asynccontextmanager
import os
import threading
import time
from typing import AsyncIterator, Any
from urllib.parse import urlparse

# Workaround for environments where tool signature evaluation runs with a globals
# dict that does not include common `typing` names (e.g. when annotations are strings
# and evaluated via `eval()` during schema generation).
# Making these names available in builtins avoids `NameError: Annotated/Literal/... is not defined`.
try:  # pragma: no cover - startup safety guard
    import builtins
    import typing as _typing

    _typing_names = (
        "Annotated",
        "Literal",
        "Any",
        "Union",
        "Optional",
        "Dict",
        "List",
        "Tuple",
        "Set",
        "FrozenSet",
    )
    for _name in _typing_names:
        if not hasattr(builtins, _name) and hasattr(_typing, _name):
            # type: ignore[attr-defined]
            setattr(builtins, _name, getattr(_typing, _name))
except Exception:
    pass

from fastmcp import FastMCP
from logging.handlers import RotatingFileHandler


class WindowsSafeRotatingFileHandler(RotatingFileHandler):
    """RotatingFileHandler that gracefully handles Windows file locking during rotation."""

    def doRollover(self):
        """Override to catch PermissionError on Windows when log file is locked."""
        try:
            super().doRollover()
        except PermissionError:
            # On Windows, another process may have the log file open.
            # Skip rotation this time - we'll try again on the next rollover.
            pass


# Configure logging using settings from config
logging.basicConfig(
    level=getattr(logging, config.log_level),
    format=config.log_format,
    stream=None,  # None -> defaults to sys.stderr; avoid stdout used by MCP stdio
    force=True    # Ensure our handler replaces any prior stdout handlers
)
logger = logging.getLogger("mcp-for-unity-server")

# Also write logs to a rotating file so logs are available when launched via stdio
try:
    _log_dir = os.path.join(os.path.expanduser(
        "~/Library/Application Support/UnityMCP"), "Logs")
    os.makedirs(_log_dir, exist_ok=True)
    _file_path = os.path.join(_log_dir, "unity_mcp_server.log")
    _fh = WindowsSafeRotatingFileHandler(
        _file_path, maxBytes=512*1024, backupCount=2, encoding="utf-8")
    _fh.setFormatter(logging.Formatter(config.log_format))
    _fh.setLevel(getattr(logging, config.log_level))
    logger.addHandler(_fh)
    logger.propagate = False  # Prevent double logging to root logger
    # Also route telemetry logger to the same rotating file and normal level
    try:
        tlog = logging.getLogger("unity-mcp-telemetry")
        tlog.setLevel(getattr(logging, config.log_level))
        tlog.addHandler(_fh)
        tlog.propagate = False  # Prevent double logging for telemetry too
    except Exception as exc:
        # Never let logging setup break startup
        logger.debug("Failed to configure telemetry logger", exc_info=exc)
except Exception as exc:
    # Never let logging setup break startup
    logger.debug("Failed to configure main logger file handler", exc_info=exc)
# Quieten noisy third-party loggers to avoid clutter during stdio handshake
for noisy in ("httpx", "urllib3", "mcp.server.lowlevel.server"):
    try:
        logging.getLogger(noisy).setLevel(
            max(logging.WARNING, getattr(logging, config.log_level)))
        logging.getLogger(noisy).propagate = False
    except Exception:
        pass

# Import telemetry only after logging is configured to ensure its logs use stderr and proper levels
# Ensure a slightly higher telemetry timeout unless explicitly overridden by env
try:

    # Ensure generous timeout unless explicitly overridden by env
    if not os.environ.get("UNITY_MCP_TELEMETRY_TIMEOUT"):
        os.environ["UNITY_MCP_TELEMETRY_TIMEOUT"] = "5.0"
except Exception:
    pass

# Global connection pool
_unity_connection_pool: UnityConnectionPool | None = None
_plugin_registry: PluginRegistry | None = None

# Cached server version (set at startup to avoid repeated I/O)
_server_version: str | None = None

# In-memory custom tool service initialized after MCP construction
custom_tool_service: CustomToolService | None = None


@asynccontextmanager
async def server_lifespan(server: FastMCP) -> AsyncIterator[dict[str, Any]]:
    """Handle server startup and shutdown."""
    global _unity_connection_pool, _server_version
    _server_version = get_package_version()
    logger.info(f"MCP for Unity Server v{_server_version} starting up")

    # Register custom tool management endpoints with FastMCP
    # Routes are declared globally below after FastMCP initialization

    # Note: When using HTTP transport, FastMCP handles the HTTP server
    # Tool registration will be handled through FastMCP endpoints
    enable_http_server = os.environ.get(
        "UNITY_MCP_ENABLE_HTTP_SERVER", "").lower() in ("1", "true", "yes", "on")
    if enable_http_server:
        http_host = os.environ.get("UNITY_MCP_HTTP_HOST", "localhost")
        http_port = int(os.environ.get("UNITY_MCP_HTTP_PORT", "8080"))
        logger.info(
            f"HTTP tool registry will be available on http://{http_host}:{http_port}")

    global _plugin_registry
    if _plugin_registry is None:
        _plugin_registry = PluginRegistry()
        loop = asyncio.get_running_loop()
        PluginHub.configure(_plugin_registry, loop)

    # Record server startup telemetry
    start_time = time.time()
    start_clk = time.perf_counter()
    # Defer initial telemetry by 1s to avoid stdio handshake interference

    def _emit_startup():
        try:
            record_telemetry(RecordType.STARTUP, {
                "server_version": _server_version,
                "startup_time": start_time,
            })
            record_milestone(MilestoneType.FIRST_STARTUP)
        except Exception:
            logger.debug("Deferred startup telemetry failed", exc_info=True)
    threading.Timer(1.0, _emit_startup).start()

    try:
        skip_connect = os.environ.get(
            "UNITY_MCP_SKIP_STARTUP_CONNECT", "").lower() in ("1", "true", "yes", "on")
        if skip_connect:
            logger.info(
                "Skipping Unity connection on startup (UNITY_MCP_SKIP_STARTUP_CONNECT=1)")
        else:
            # Initialize connection pool and discover instances
            _unity_connection_pool = get_unity_connection_pool()
            instances = _unity_connection_pool.discover_all_instances()

            if instances:
                logger.info(
                    f"Discovered {len(instances)} Unity instance(s): {[i.id for i in instances]}")

                # Try to connect to default instance
                try:
                    _unity_connection_pool.get_connection()
                    logger.info(
                        "Connected to default Unity instance on startup")

                    # Record successful Unity connection (deferred)
                    threading.Timer(1.0, lambda: record_telemetry(
                        RecordType.UNITY_CONNECTION,
                        {
                            "status": "connected",
                            "connection_time_ms": (time.perf_counter() - start_clk) * 1000,
                            "instance_count": len(instances)
                        }
                    )).start()
                except Exception as e:
                    logger.warning(
                        f"Could not connect to default Unity instance: {e}")
            else:
                logger.warning("No Unity instances found on startup")

    except ConnectionError as e:
        logger.warning(f"Could not connect to Unity on startup: {e}")

        # Record connection failure (deferred)
        _err_msg = str(e)[:200]
        threading.Timer(1.0, lambda: record_telemetry(
            RecordType.UNITY_CONNECTION,
            {
                "status": "failed",
                "error": _err_msg,
                "connection_time_ms": (time.perf_counter() - start_clk) * 1000,
            }
        )).start()
    except Exception as e:
        logger.warning(f"Unexpected error connecting to Unity on startup: {e}")
        _err_msg = str(e)[:200]
        threading.Timer(1.0, lambda: record_telemetry(
            RecordType.UNITY_CONNECTION,
            {
                "status": "failed",
                "error": _err_msg,
                "connection_time_ms": (time.perf_counter() - start_clk) * 1000,
            }
        )).start()

    try:
        # Yield shared state for lifespan consumers (e.g., middleware)
        yield {
            "pool": _unity_connection_pool,
            "plugin_registry": _plugin_registry,
        }
    finally:
        if _unity_connection_pool:
            _unity_connection_pool.disconnect_all()
        logger.info("MCP for Unity Server shut down")


def _build_instructions(project_scoped_tools: bool) -> str:
    if project_scoped_tools:
        custom_tools_note = (
            "I have a dynamic tool system. Always check the mcpforunity://custom-tools resource first "
            "to see what special capabilities are available for the current project."
        )
    else:
        custom_tools_note = (
            "Custom tools are registered as standard tools when Unity connects. "
            "No project-scoped custom tools resource is available."
        )

    return f"""
This server provides tools to interact with the Unity Game Engine Editor.

{custom_tools_note}

Targeting Unity instances:
- Use the resource mcpforunity://instances to list active Unity sessions (Name@hash).
- When multiple instances are connected, call set_active_instance with the exact Name@hash before using tools/resources. The server will error if multiple are connected and no active instance is set.

Important Workflows:

Resources vs Tools:
- Use RESOURCES to read editor state (editor_state, project_info, project_tags, tests, etc)
- Use TOOLS to perform actions and mutations (manage_editor for play mode control, tag/layer management, etc)
- Always check related resources before modifying the engine state with tools

Script Management:
- After creating or modifying scripts (by your own tools or the `manage_script` tool) use `read_console` to check for compilation errors before proceeding
- Only after successful compilation can new components/types be used
- You can poll the `editor_state` resource's `isCompiling` field to check if the domain reload is complete

Scene Setup:
- Always include a Camera and main Light (Directional Light) in new scenes
- Create prefabs with `manage_asset` for reusable GameObjects
- Use `manage_scene` to load, save, and query scene information

Path Conventions:
- Unless specified otherwise, all paths are relative to the project's `Assets/` folder
- Use forward slashes (/) in paths for cross-platform compatibility

Console Monitoring:
- Check `read_console` regularly to catch errors, warnings, and compilation status
- Filter by log type (Error, Warning, Log) to focus on specific issues

Menu Items:
- Use `execute_menu_item` when you have read the menu items resource
- This lets you interact with Unity's menu system and third-party tools

Payload sizing & paging (important):
- Many Unity queries can return very large JSON. Prefer **paged + summary-first** calls.
- `manage_scene(action="get_hierarchy")`:
  - Use `page_size` + `cursor` and follow `next_cursor` until null.
  - `page_size` is **items per page**; recommended starting point: **50**.
- `manage_gameobject(action="get_components")`:
  - Start with `include_properties=false` (metadata-only) and small `page_size` (e.g. **10-25**).
  - Only request `include_properties=true` when needed; keep `page_size` small (e.g. **3-10**) to bound payloads.
- `manage_asset(action="search")`:
  - Use paging (`page_size`, `page_number`) and keep `page_size` modest (e.g. **25-50**) to avoid token-heavy responses.
  - Keep `generate_preview=false` unless you explicitly need thumbnails (previews may include large base64 payloads).
"""


def _normalize_instance_token(instance_token: str | None) -> tuple[str | None, str | None]:
    if not instance_token:
        return None, None
    if "@" in instance_token:
        name_part, _, hash_part = instance_token.partition("@")
        return (name_part or None), (hash_part or None)
    return None, instance_token


def create_mcp_server(project_scoped_tools: bool) -> FastMCP:
    mcp = FastMCP(
        name="mcp-for-unity-server",
        lifespan=server_lifespan,
        instructions=_build_instructions(project_scoped_tools),
    )

    global custom_tool_service
    custom_tool_service = CustomToolService(
        mcp, project_scoped_tools=project_scoped_tools)

    @mcp.custom_route("/health", methods=["GET"])
    async def health_http(_: Request) -> JSONResponse:
        return JSONResponse({
            "status": "healthy",
            "timestamp": time.time(),
            "version": _server_version or "unknown",
            "message": "MCP for Unity server is running"
        })

    @mcp.custom_route("/api/auth/login-url", methods=["GET"])
    async def auth_login_url(_: Request) -> JSONResponse:
        """Return the login URL for users to obtain/manage API keys."""
        if not config.api_key_login_url:
            return JSONResponse(
                {
                    "success": False,
                    "error": "API key management not configured. Contact your server administrator.",
                },
                status_code=404,
            )
        return JSONResponse({
            "success": True,
            "login_url": config.api_key_login_url,
        })

    # Only expose CLI routes if running locally (not in remote hosted mode)
    if not config.http_remote_hosted:
        @mcp.custom_route("/api/command", methods=["POST"])
        async def cli_command_route(request: Request) -> JSONResponse:
            """REST endpoint for CLI commands to Unity."""
            try:
                body = await request.json()

                command_type = body.get("type")
                params = body.get("params", {})
                unity_instance = body.get("unity_instance")

                if not command_type:
                    return JSONResponse({"success": False, "error": "Missing 'type' field"}, status_code=400)

                # Get available sessions
                sessions = await PluginHub.get_sessions()
                if not sessions.sessions:
                    return JSONResponse({
                        "success": False,
                        "error": "No Unity instances connected. Make sure Unity is running with MCP plugin."
                    }, status_code=503)

                # Find target session
                session_id = None
                session_details = None
                instance_name, instance_hash = _normalize_instance_token(
                    unity_instance)
                if unity_instance:
                    # Try to match by hash or project name
                    for sid, details in sessions.sessions.items():
                        if details.hash == instance_hash or details.project in (instance_name, unity_instance):
                            session_id = sid
                            session_details = details
                            break

                    # If a specific unity_instance was requested but not found, return an error
                    if not session_id:
                        return JSONResponse(
                            {
                                "success": False,
                                "error": f"Unity instance '{unity_instance}' not found",
                            },
                            status_code=404,
                        )
                else:
                    # No specific unity_instance requested: use first available session
                    session_id = next(iter(sessions.sessions.keys()))
                    session_details = sessions.sessions.get(session_id)

                    if command_type == "execute_custom_tool":
                        tool_name = None
                        tool_params = {}
                        if isinstance(params, dict):
                            tool_name = params.get(
                                "tool_name") or params.get("name")
                            tool_params = params.get(
                                "parameters") or params.get("params") or {}

                        if not tool_name:
                            return JSONResponse(
                                {"success": False,
                                    "error": "Missing 'tool_name' for execute_custom_tool"},
                                status_code=400,
                            )
                        if tool_params is None:
                            tool_params = {}
                        if not isinstance(tool_params, dict):
                            return JSONResponse(
                                {"success": False,
                                    "error": "Tool parameters must be an object/dict"},
                                status_code=400,
                            )

                        # Prefer a concrete hash for project-scoped tools.
                        unity_instance_hint = unity_instance
                        if session_details and session_details.hash:
                            unity_instance_hint = session_details.hash

                        project_id = resolve_project_id_for_unity_instance(
                            unity_instance_hint)
                        if not project_id:
                            return JSONResponse(
                                {"success": False,
                                    "error": "Could not resolve project id for custom tool"},
                                status_code=400,
                            )

                        service = CustomToolService.get_instance()
                        result = await service.execute_tool(
                            project_id, tool_name, unity_instance_hint, tool_params
                        )
                        return JSONResponse(result.model_dump())

                # Send command to Unity
                result = await PluginHub.send_command(session_id, command_type, params)
                return JSONResponse(result)

            except Exception as e:
                logger.exception("CLI command error: %s", e)
                return JSONResponse({"success": False, "error": str(e)}, status_code=500)

        @mcp.custom_route("/api/instances", methods=["GET"])
        async def cli_instances_route(_: Request) -> JSONResponse:
            """REST endpoint to list connected Unity instances."""
            try:
                sessions = await PluginHub.get_sessions()
                instances = []
                for session_id, details in sessions.sessions.items():
                    instances.append({
                        "session_id": session_id,
                        "project": details.project,
                        "hash": details.hash,
                        "unity_version": details.unity_version,
                        "connected_at": details.connected_at,
                    })
                return JSONResponse({"success": True, "instances": instances})
            except Exception as e:
                return JSONResponse({"success": False, "error": str(e)}, status_code=500)

        @mcp.custom_route("/api/custom-tools", methods=["GET"])
        async def cli_custom_tools_route(request: Request) -> JSONResponse:
            """REST endpoint to list custom tools for the active Unity project."""
            try:
                unity_instance = request.query_params.get("instance")
                instance_name, instance_hash = _normalize_instance_token(
                    unity_instance)

                sessions = await PluginHub.get_sessions()
                if not sessions.sessions:
                    return JSONResponse({
                        "success": False,
                        "error": "No Unity instances connected. Make sure Unity is running with MCP plugin."
                    }, status_code=503)

                session_details = None
                if unity_instance:
                    # Try to match by hash or project name
                    for _, details in sessions.sessions.items():
                        if details.hash == instance_hash or details.project in (instance_name, unity_instance):
                            session_details = details
                            break
                    if not session_details:
                        return JSONResponse(
                            {
                                "success": False,
                                "error": f"Unity instance '{unity_instance}' not found",
                            },
                            status_code=404,
                        )
                else:
                    # No specific unity_instance requested: use first available session
                    session_details = next(iter(sessions.sessions.values()))

                unity_instance_hint = unity_instance
                if session_details and session_details.hash:
                    unity_instance_hint = session_details.hash

                project_id = resolve_project_id_for_unity_instance(
                    unity_instance_hint)
                if not project_id:
                    return JSONResponse(
                        {"success": False,
                            "error": "Could not resolve project id for custom tools"},
                        status_code=400,
                    )

                service = CustomToolService.get_instance()
                tools = await service.list_registered_tools(project_id)
                tools_payload = [
                    tool.model_dump() if hasattr(tool, "model_dump") else tool for tool in tools
                ]

                return JSONResponse({
                    "success": True,
                    "project_id": project_id,
                    "tool_count": len(tools_payload),
                    "tools": tools_payload,
                })
            except Exception as e:
                logger.exception("CLI custom tools error: %s", e)
                return JSONResponse({"success": False, "error": str(e)}, status_code=500)

    # Initialize and register middleware for session-based Unity instance routing
    # Using the singleton getter ensures we use the same instance everywhere
    unity_middleware = get_unity_instance_middleware()
    mcp.add_middleware(unity_middleware)
    logger.info("Registered Unity instance middleware for session-based routing")

    # Initialize API key authentication if in remote-hosted mode
    if config.http_remote_hosted and config.api_key_validation_url:
        ApiKeyService(
            validation_url=config.api_key_validation_url,
            cache_ttl=config.api_key_cache_ttl,
            service_token_header=config.api_key_service_token_header,
            service_token=config.api_key_service_token,
        )
        logger.info(
            "Initialized API key authentication service (validation URL: %s, TTL: %.0fs)",
            config.api_key_validation_url,
            config.api_key_cache_ttl,
        )

    # Mount plugin websocket hub at /hub/plugin when HTTP transport is active
    existing_routes = [
        route for route in mcp._get_additional_http_routes()
        if isinstance(route, WebSocketRoute) and route.path == "/hub/plugin"
    ]
    if not existing_routes:
        mcp._additional_http_routes.append(
            WebSocketRoute("/hub/plugin", PluginHub))

    # Register all tools
    register_all_tools(mcp, project_scoped_tools=project_scoped_tools)

    # Register all resources
    register_all_resources(mcp, project_scoped_tools=project_scoped_tools)

    return mcp


def main():
    """Entry point for uvx and console scripts."""
    parser = argparse.ArgumentParser(
        description="MCP for Unity Server",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Environment Variables:
  UNITY_MCP_DEFAULT_INSTANCE   Default Unity instance to target (project name, hash, or 'Name@hash')
  UNITY_MCP_SKIP_STARTUP_CONNECT   Skip initial Unity connection attempt (set to 1/true/yes/on)
  UNITY_MCP_TELEMETRY_ENABLED   Enable telemetry (set to 1/true/yes/on)
  UNITY_MCP_TRANSPORT   Transport protocol: stdio or http (default: stdio)
  UNITY_MCP_HTTP_URL   HTTP server URL (default: http://localhost:8080)
  UNITY_MCP_HTTP_HOST   HTTP server host (overrides URL host)
  UNITY_MCP_HTTP_PORT   HTTP server port (overrides URL port)

Examples:
  # Use specific Unity project as default
  python -m src.server --default-instance "MyProject"

  # Start with HTTP transport
  python -m src.server --transport http --http-url http://localhost:8080

  # Start with stdio transport (default)
  python -m src.server --transport stdio

  # Use environment variable for transport
  UNITY_MCP_TRANSPORT=http UNITY_MCP_HTTP_URL=http://localhost:9000 python -m src.server
        """
    )
    parser.add_argument(
        "--default-instance",
        type=str,
        metavar="INSTANCE",
        help="Default Unity instance to target (project name, hash, or 'Name@hash'). "
             "Overrides UNITY_MCP_DEFAULT_INSTANCE environment variable."
    )
    parser.add_argument(
        "--transport",
        type=str,
        choices=["stdio", "http"],
        default="stdio",
        help="Transport protocol to use: stdio or http (default: stdio). "
             "Overrides UNITY_MCP_TRANSPORT environment variable."
    )
    parser.add_argument(
        "--http-url",
        type=str,
        default="http://localhost:8080",
        metavar="URL",
        help="HTTP server URL (default: http://localhost:8080). "
             "Can also set via UNITY_MCP_HTTP_URL environment variable."
    )
    parser.add_argument(
        "--http-host",
        type=str,
        default=None,
        metavar="HOST",
        help="HTTP server host (overrides URL host). "
             "Overrides UNITY_MCP_HTTP_HOST environment variable."
    )
    parser.add_argument(
        "--http-port",
        type=int,
        default=None,
        metavar="PORT",
        help="HTTP server port (overrides URL port). "
             "Overrides UNITY_MCP_HTTP_PORT environment variable."
    )
    parser.add_argument(
        "--http-remote-hosted",
        action="store_true",
        help="Treat HTTP transport as remotely hosted (forces explicit Unity instance selection). "
             "Can also set via UNITY_MCP_HTTP_REMOTE_HOSTED=true."
    )
    parser.add_argument(
        "--api-key-validation-url",
        type=str,
        default=None,
        metavar="URL",
        help="External URL to validate API keys (POST with {'api_key': '...'}). "
             "Required when --http-remote-hosted is set. "
             "Can also set via UNITY_MCP_API_KEY_VALIDATION_URL."
    )
    parser.add_argument(
        "--api-key-login-url",
        type=str,
        default=None,
        metavar="URL",
        help="URL where users can obtain/manage API keys. "
             "Returned by /api/auth/login-url endpoint. "
             "Can also set via UNITY_MCP_API_KEY_LOGIN_URL."
    )
    parser.add_argument(
        "--api-key-cache-ttl",
        type=float,
        default=300.0,
        metavar="SECONDS",
        help="Cache TTL for validated API keys in seconds (default: 300). "
             "Can also set via UNITY_MCP_API_KEY_CACHE_TTL."
    )
    parser.add_argument(
        "--api-key-service-token-header",
        type=str,
        default=None,
        metavar="HEADER",
        help="Header name for service token sent to validation endpoint (e.g. X-Service-Token). "
             "Can also set via UNITY_MCP_API_KEY_SERVICE_TOKEN_HEADER."
    )
    parser.add_argument(
        "--api-key-service-token",
        type=str,
        default=None,
        metavar="TOKEN",
        help="Service token value sent to validation endpoint for server authentication. "
             "WARNING: Prefer UNITY_MCP_API_KEY_SERVICE_TOKEN env var in production to avoid process listing exposure."
    )
    parser.add_argument(
        "--unity-instance-token",
        type=str,
        default=None,
        metavar="TOKEN",
        help="Optional per-launch token set by Unity for deterministic lifecycle management. "
             "Used by Unity to validate it is stopping the correct process."
    )
    parser.add_argument(
        "--pidfile",
        type=str,
        default=None,
        metavar="PATH",
        help="Optional path where the server will write its PID on startup. "
             "Used by Unity to stop the exact process it launched when running in a terminal."
    )
    parser.add_argument(
        "--project-scoped-tools",
        action="store_true",
        help="Keep custom tools scoped to the active Unity project and enable the custom tools resource. "
             "Can also set via UNITY_MCP_PROJECT_SCOPED_TOOLS=true."
    )

    args = parser.parse_args()

    # Set environment variables from command line args
    if args.default_instance:
        os.environ["UNITY_MCP_DEFAULT_INSTANCE"] = args.default_instance
        logger.info(
            f"Using default Unity instance from command-line: {args.default_instance}")

    # Set transport mode
    config.transport_mode = args.transport or os.environ.get(
        "UNITY_MCP_TRANSPORT", "stdio")
    logger.info(f"Transport mode: {config.transport_mode}")

    config.http_remote_hosted = (
        bool(args.http_remote_hosted)
        or os.environ.get("UNITY_MCP_HTTP_REMOTE_HOSTED", "").lower() in ("true", "1", "yes", "on")
    )

    # API key authentication configuration
    config.api_key_validation_url = (
        args.api_key_validation_url
        or os.environ.get("UNITY_MCP_API_KEY_VALIDATION_URL")
    )
    config.api_key_login_url = (
        args.api_key_login_url
        or os.environ.get("UNITY_MCP_API_KEY_LOGIN_URL")
    )
    try:
        cache_ttl_env = os.environ.get("UNITY_MCP_API_KEY_CACHE_TTL")
        config.api_key_cache_ttl = (
            float(cache_ttl_env) if cache_ttl_env else args.api_key_cache_ttl
        )
    except ValueError:
        logger.warning(
            "Invalid UNITY_MCP_API_KEY_CACHE_TTL value, using default 300.0"
        )
        config.api_key_cache_ttl = 300.0

    # Service token for authenticating to validation endpoint
    config.api_key_service_token_header = (
        args.api_key_service_token_header
        or os.environ.get("UNITY_MCP_API_KEY_SERVICE_TOKEN_HEADER")
    )
    config.api_key_service_token = (
        args.api_key_service_token
        or os.environ.get("UNITY_MCP_API_KEY_SERVICE_TOKEN")
    )

    # Validate: remote-hosted HTTP mode requires API key validation URL
    if config.http_remote_hosted and config.transport_mode == "http" and not config.api_key_validation_url:
        logger.error(
            "--http-remote-hosted requires --api-key-validation-url or "
            "UNITY_MCP_API_KEY_VALIDATION_URL environment variable"
        )
        raise SystemExit(1)

    http_url = os.environ.get("UNITY_MCP_HTTP_URL", args.http_url)
    parsed_url = urlparse(http_url)

    # Allow individual host/port to override URL components
    http_host = args.http_host or os.environ.get(
        "UNITY_MCP_HTTP_HOST") or parsed_url.hostname or "localhost"

    # Safely parse optional environment port (may be None or non-numeric)
    _env_port_str = os.environ.get("UNITY_MCP_HTTP_PORT")
    try:
        _env_port = int(_env_port_str) if _env_port_str is not None else None
    except ValueError:
        logger.warning(
            "Invalid UNITY_MCP_HTTP_PORT value '%s', ignoring", _env_port_str)
        _env_port = None

    http_port = args.http_port or _env_port or parsed_url.port or 8080

    os.environ["UNITY_MCP_HTTP_HOST"] = http_host
    os.environ["UNITY_MCP_HTTP_PORT"] = str(http_port)

    # Optional lifecycle handshake for Unity-managed terminal launches
    if args.unity_instance_token:
        os.environ["UNITY_MCP_INSTANCE_TOKEN"] = args.unity_instance_token
    if args.pidfile:
        try:
            pid_dir = os.path.dirname(args.pidfile)
            if pid_dir:
                os.makedirs(pid_dir, exist_ok=True)
            with open(args.pidfile, "w", encoding="ascii") as f:
                f.write(str(os.getpid()))
        except Exception as exc:
            logger.warning(
                "Failed to write pidfile '%s': %s", args.pidfile, exc)

    if args.http_url != "http://localhost:8080":
        logger.info(f"HTTP URL set to: {http_url}")
    if args.http_host:
        logger.info(f"HTTP host override: {http_host}")
    if args.http_port:
        logger.info(f"HTTP port override: {http_port}")

    project_scoped_tools = (
        bool(args.project_scoped_tools)
        or os.environ.get("UNITY_MCP_PROJECT_SCOPED_TOOLS", "").lower() in ("true", "1", "yes", "on")
    )
    mcp = create_mcp_server(project_scoped_tools)

    # Determine transport mode
    if config.transport_mode == 'http':
        # Use HTTP transport for FastMCP
        transport = 'http'
        # Use the parsed host and port from URL/args
        http_url = os.environ.get("UNITY_MCP_HTTP_URL", args.http_url)
        parsed_url = urlparse(http_url)
        host = args.http_host or os.environ.get(
            "UNITY_MCP_HTTP_HOST") or parsed_url.hostname or "localhost"
        port = args.http_port or _env_port or parsed_url.port or 8080
        logger.info(f"Starting FastMCP with HTTP transport on {host}:{port}")
        mcp.run(transport=transport, host=host, port=port)
    else:
        # Use stdio transport for traditional MCP
        logger.info("Starting FastMCP with stdio transport")
        mcp.run(transport='stdio')


# Run the server
if __name__ == "__main__":
    main()