Errors and retries

import json
import os
import random
import time
import urllib.error
import urllib.request
import uuid

BASE_URL = os.environ.get("TYPESAFE_BASE_URL", "https://api.sieve.one")
API_KEY = os.environ["TYPESAFE_API_KEY"]
RETRYABLE = {429, 500, 503, 504, 529}


def system_one(body, max_attempts=4):
    data = json.dumps(body).encode()
    idempotency_key = str(uuid.uuid4())  # the same key on every attempt
    for attempt in range(1, max_attempts + 1):
        request = urllib.request.Request(
            f"{BASE_URL}/v1/systemone",
            data=data,
            method="POST",
            headers={
                "Authorization": f"Bearer {API_KEY}",
                "Content-Type": "application/json",
                "Idempotency-Key": idempotency_key,
            },
        )
        try:
            with urllib.request.urlopen(request, timeout=60) as response:
                return json.load(response)
        except urllib.error.HTTPError as error:
            detail = error.read().decode()
            retry_after = error.headers.get("retry-after")
            request_id = error.headers.get("x-typesafe-request-id")
            give_up = (
                error.code not in RETRYABLE
                or attempt == max_attempts
                or error.headers.get("x-should-retry") == "false"
                or (error.code == 429 and retry_after is None)  # no credit or a daily limit
            )
            if give_up:
                raise RuntimeError(f"HTTP {error.code} (request {request_id}): {detail}") from None
            delay = float(retry_after) if retry_after else min(2 ** attempt, 20) * random.uniform(0.5, 1.0)
        except (urllib.error.URLError, TimeoutError):
            if attempt == max_attempts:
                raise
            delay = min(2 ** attempt, 20) * random.uniform(0.5, 1.0)
        time.sleep(delay)


answer = system_one({
    "model": "sieve-latest",
    "state": "I was charged twice. Please fix this ASAP.",
    "questions": {"billing": {"type": "noul", "instructions": "Is this message about billing?"}},
})
print(answer["answers"]["billing"]["noul"])