scheduled-email 0.1.0

Auto-rotating secret generation with Argon2 hashing and scheduled SMTP delivery

scheduled-email

Auto-rotating secret generation — creates Argon2-hashed secrets and delivers password-less login links via SMTP on a configurable schedule.

Install

pip install scheduled-email

尚未发布到 PyPI 前，需先按 PUBLISH.md 完成上传。 本地开发可用 editable 模式：pip install -e packages/scheduled-email

Environment Variables

Variable	Required	Default	Description
SCHEDMAIL_SMTP_USER	yes	—	Sender email address
SCHEDMAIL_SMTP_PASS	yes	—	SMTP authorization code
SCHEDMAIL_RECIPIENT	yes	—	Recipient email address
SCHEDMAIL_BASE_URL	no	https://example.com/login?token=	Prefix for login URL
SCHEDMAIL_ROTATE_HOURS	no	24	Rotation interval (hours)
SCHEDMAIL_SCT	no	*****-daiju	SCT constant
SCHEDMAIL_MASK_SECRET	no	false	Mask secret in email body

Copy .env.example to .env and fill in credentials. Never commit .env.

Usage

Standalone

from scheduled_email import start, stop

svc = start()       # immediate first rotation + email, then every 24h
# ...
stop()               # cancel timer

Context Manager

from scheduled_email import ScheduledEmailService

with ScheduledEmailService() as svc:
    print(svc.current_url)

FastAPI Integration (minimal)

from contextlib import asynccontextmanager
from fastapi import FastAPI

@asynccontextmanager
async def lifespan(app: FastAPI):
    from scheduled_email import start, stop
    start()
    yield
    stop()

app = FastAPI(lifespan=lifespan)

How It Works

1. On start(), a 32-byte random secret is generated via secrets.token_urlsafe.
2. The secret is hashed with Argon2 (argon2-cffi).
3. A login URL is built: {SCHEDMAIL_BASE_URL}{argon2_hash}.
4. An email is sent via SMTP_SSL containing: rotation time, SCT, secret (optionally masked), and the full login URL.
5. A threading.Timer schedules the next rotation after SCHEDMAIL_ROTATE_HOURS.