Synthesia auto top-up vs Sume: manual dashboard top-ups

Synthesia now lets you buy credits and set automatic top-ups so long-running jobs do not fail when the balance runs low (update dated 9/9/2026). Sume has no auto top-up in its docs: top-up is a manual, Stripe-backed dashboard action, and a job that cannot be paid for is refused at submit with 402 insufficient_credits.

Synthesia's wording is from its updates page; Sume's from the Credits docs and generation admission, read 2026-10-01.

How does a Sume top-up work?

The dashboard can start a Stripe-backed manual credit top-up when billing is configured for the workspace. After checkout completes, the usage ledger can show the top-up activity and the updated balance. The docs tell API clients to treat top-ups as dashboard operations: the public API exposes balance and usage reads, not top-up creation.

Does a low balance kill a running job?

The docs place the check at the front: generation submit fails with 402 insufficient_credits before provider work starts. This page does not cover what happens to a job already running, so do not assume more than the docs say.

Side by side

What should I do for long batches?

Check your balance before a batch, top up in the dashboard if needed, and handle a 402 in your code by pausing rather than retrying blindly. See insufficient credits 402.