A failed Sume video poll has error as a string, not an error object

A 200 poll with status failed carries error as a plain string, while a real HTTP error such as 402 or 429 carries an envelope {error:{code,message,request_id,details}}. Code that reads poll.error.message on a failed job gets undefined in TypeScript or a TypeError in Python.

Two places an error can live

The poll body is a bare object with id, generation_id, polling_url, status, model, unsigned_urls, usage and error. When the job failed, error is the text. When the poll request itself fails, you get a non-2xx status and the envelope.

Handle both, and log the x-sume-request-id response header on the second case; the string case has no code to branch on.

A reader that handles both

The function returns one string for logs and never raises on shape.

def error_text(status_code, body):
    err = body.get("error")
    if isinstance(err, str):
        return err  # failed poll: plain text
    if isinstance(err, dict):
        code = err.get("code", "error")
        return f"{status_code} {code}: {err.get('message', '')}"
    return f"{status_code} unknown error"

# poll = requests.get(polling_url, headers=h)
# if poll.json()["status"] == "failed":
#     print(error_text(poll.status_code, poll.json()))

Gotchas

A failed job is not a reason to resubmit blindly: check the text first. A bad input URL is fixed by changing the input, and each resubmit of a 30 s Wan 3.0 clip at 720p reserves $3.75 again, so three blind tries reserve 3 x $3.75 = $11.25.

The docs sample uses status.get('error', 'Unknown error') in Python and status.error ?? 'Unknown error' in TypeScript, which is the same idea in one line.