without-env

A without Context backed by environment variables: the simplest possible context, a static one loaded at startup and never changed. See the without_env API reference for the full surface.

EnvContext.load(MySettings) reads the environment once, at the boundary, into a validated pydantic-settings model (parse, don't validate), then hands that immutable value to processors via current(). Because it never changes, a reloading source (a watched file, a ConfigMap mount) is a separate plugin; see without-configmap for the context-updated-by-a-stream case.

from pydantic_settings import BaseSettings
from without_env import EnvContext


class Settings(BaseSettings):
    default_mode: str = "upper"
    max_bytes: int = 1_048_576


config = EnvContext.load(Settings)   # reads os.environ once, validates
config.current().default_mode        # the parsed value, same every call

A missing required field or a value that fails validation raises from pydantic-settings at load time, so misconfiguration fails loudly at startup rather than at first use.