AI動画APIのエラーコード：意味と再試行すべきタイミング

import os
import time
import uuid

import requests

API = "https://api.revana.si/v1"
AUTH = {"Authorization": f"Bearer {os.environ['REVANA_API_KEY']}"}
RETRY_HTTP = {429, 500, 503}


class GenerationError(Exception):
    pass


def submit(body):
    """POST a job. Retries 429, 500 and 503 with the same Idempotency-Key, so a retry never starts a second job."""
    headers = {**AUTH, "Idempotency-Key": str(uuid.uuid4())}
    for attempt in range(6):
        r = requests.post(f"{API}/generations", headers=headers, json=body, timeout=60)
        if r.ok:
            return r.json()
        if r.status_code in RETRY_HTTP:
            time.sleep(float(r.headers.get("Retry-After", 2 ** attempt)))
            continue
        err = r.json()["error"]  # 400, 401, 402, 403, 409, 413, 422: fix the request, do not retry
        raise GenerationError(f"{r.status_code} {err['code']}: {err['message']}")
    raise GenerationError("still busy after 6 tries")


def wait(job):
    while job["status"] in ("queued", "running"):
        time.sleep(5)
        job = requests.get(f"{API}/generations/{job['id']}", headers=AUTH).json()
    return job


def generate(body, tries=3):
    for n in range(tries):
        job = wait(submit(body))  # each call uses a new key: a failed job is final
        if job["status"] == "succeeded":
            return job
        err = job["error"]
        if not err["retryable"]:
            raise GenerationError(f"{err['code']}: {err['message']}")
        time.sleep(60 * (n + 1))  # model_busy, timeout and the like: wait, then try again
    raise GenerationError(f"gave up after {tries} tries: {err['code']}")


job = generate({
    "model": "seedance-2.0-fast",
    "input": {"prompt": "Waves roll onto black sand at sunset.", "resolution": "480p", "duration": 5},
    "max_cost_usd": 0.3,
})
print(job["output"]["urls"][0], job["cost_usd"])