JWT Sign + Verify (PyJWT)

import jwt    # pip install PyJWT
import time

SECRET = "change-me"

def issue_token(user_id: int, ttl_sec: int = 3600) -> str:
    payload = {
        "sub":  str(user_id),
        "iat":  int(time.time()),
        "exp":  int(time.time()) + ttl_sec,
        "role": "user",
    }
    return jwt.encode(payload, SECRET, algorithm="HS256")

def verify_token(token: str) -> dict | None:
    try:
        return jwt.decode(token, SECRET, algorithms=["HS256"])
    except jwt.ExpiredSignatureError:
        print("token expired")
    except jwt.InvalidTokenError as e:
        print("invalid:", e)
    return None

t = issue_token(42)
print(verify_token(t))      # {'sub': '42', 'iat': …, 'exp': …, 'role': 'user'}