"""Configuration module for portfolio-mcp Server.
Uses pydantic-settings for environment-based configuration with validation.
Environment Variables:
CACHE_BACKEND: Cache backend type - memory, sqlite, redis (default: auto)
REDIS_URL: Redis connection URL (default: redis://localhost:6379)
SQLITE_PATH: SQLite database path (default: XDG data dir)
PORTFOLIO_MCP_PORT: Server port for HTTP modes (default: 8000)
PORTFOLIO_MCP_HOST: Server host for HTTP modes (default: 0.0.0.0)
"""
from __future__ import annotations
import os
from functools import lru_cache
from pathlib import Path
from typing import Literal
from pydantic import Field, field_validator
from pydantic_settings import BaseSettings, SettingsConfigDict
def _get_default_sqlite_path() -> str:
"""Get XDG-compliant default SQLite path."""
xdg_data_home = os.environ.get("XDG_DATA_HOME")
if xdg_data_home:
base_dir = Path(xdg_data_home)
else:
base_dir = Path.home() / ".local" / "share"
return str(base_dir / "portfolio-mcp" / "cache.db")
class Settings(BaseSettings):
"""Application settings loaded from environment variables."""
model_config = SettingsConfigDict(
env_prefix="",
case_sensitive=False,
extra="ignore",
)
# Cache backend configuration
cache_backend: Literal["memory", "sqlite", "redis", "auto"] = Field(
default="auto",
description=(
"Cache backend type. 'auto' selects sqlite for stdio, redis for HTTP modes."
),
)
redis_url: str = Field(
default="redis://localhost:6379",
description="Redis connection URL for distributed caching.",
)
sqlite_path: str = Field(
default_factory=_get_default_sqlite_path,
description="SQLite database path for local persistence.",
)
# Server configuration (for HTTP modes)
portfolio_mcp_port: int = Field(
default=8000,
ge=1,
le=65535,
description="Server port for SSE and streamable-http modes.",
)
portfolio_mcp_host: str = Field(
default="0.0.0.0", # nosec B104 - intentional for Docker/container deployments
description="Server host for SSE and streamable-http modes.",
)
# Portfolio-specific configuration
default_risk_free_rate: float = Field(
default=0.02,
ge=0.0,
le=1.0,
description="Default risk-free rate for portfolio calculations (e.g., 0.02 = 2%).",
)
default_trading_days: int = Field(
default=252,
ge=1,
le=365,
description="Default number of trading days per year for annualization.",
)
@field_validator("sqlite_path")
@classmethod
def expand_sqlite_path(cls, value: str) -> str:
"""Expand ~ in SQLite path."""
return str(Path(value).expanduser())
def get_cache_backend_for_transport(
self,
transport: Literal["stdio", "sse", "streamable-http"],
) -> Literal["memory", "sqlite", "redis"]:
"""Get the appropriate cache backend for the given transport.
Args:
transport: The MCP transport mode being used.
Returns:
The cache backend to use.
"""
if self.cache_backend != "auto":
# Explicit backend configured
return self.cache_backend
# Auto-select based on transport
if transport == "stdio":
return "sqlite"
else:
# HTTP modes (sse, streamable-http) use Redis for distributed caching
return "redis"
@lru_cache
def get_settings() -> Settings:
"""Get cached settings instance.
Returns:
Singleton Settings instance loaded from environment.
"""
return Settings()
# Convenience export for direct access
settings = get_settings()
