Preflight a mixed 30 s batch: 2 Seedance and 4 Wan needs $49.67

Two 30 s Seedance 2.5 clips at 720p ($17.334 each) and four 30 s Wan 3.0 clips at 720p ($3.75 each) reserve $49.668 at submit, which is 49,668,000 USD micros. Read GET /v1/balance, compare the integer available_amount_usd_micros, and a 402 insufficient_credits never lands in the middle of the batch.

The reserve, line by line

Six jobs also fit inside the Free plan's 6 accepted jobs (1 processing plus 5 queued), so the batch is not blocked by admission on any plan.

A 402 means no job was started for that request. Earlier jobs in the batch are already reserved, which is why checking first is cleaner than failing at job five.

The preflight

The balance response is wrapped as data.balance. Keep the amounts as integers so there is no float comparison.

import os
import requests

H = {"Authorization": f"Bearer {os.environ['SUME_API_KEY']}"}
need_micros = 2 * 17_334_000 + 4 * 3_750_000  # 49_668_000

r = requests.get("https://api.sume.com/v1/balance", headers=H, timeout=30)
r.raise_for_status()
bal = r.json()["data"]["balance"]
have = bal["available_amount_usd_micros"]
if bal["state"] == "empty" or have < need_micros:
    raise SystemExit(f"need {need_micros} micros, have {have}")
print("ok to submit 6 clips")

Gotchas

The check is advisory: other clients on the same workspace can spend between your read and your first submit. Keep the 402 handler anyway, and send an Idempotency-Key on every submit so a retry cannot double-book.

Estimates from the pricing code are a forecast. The poll's usage.cost is the receipt, so compare the two after the first job.