FastAPI Settings

Settings with Pydantic

from pydantic_settings import BaseSettings, SettingsConfigDict
from functools import lru_cache

class Settings(BaseSettings):
    app_name:     str     = "My API"
    debug:        bool    = False
    database_url: str
    secret_key:   str
    redis_url:    str     = "redis://localhost:6379"
    cors_origins: list[str] = ["http://localhost:3000"]
    jwt_expire_minutes: int = 60

    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        case_sensitive=False,
    )

# Cached settings — only read once
@lru_cache()
def get_settings() -> Settings:
    return Settings()

# Use as dependency
@app.get("/info")
def app_info(settings: Settings = Depends(get_settings)):
    return {"app": settings.app_name, "debug": settings.debug}