Runway Tier 1 caps spend at $100 a month; Sume returns 402 at balance

Runway's lowest API tier, Tier 1, has a $100 monthly spend cap and one or two concurrent tasks, and accounts move up tiers as they spend. Sume does not use a spend ladder: it checks the workspace balance at submit, and if the estimate cannot be reserved it returns 402 insufficient_credits before any provider work starts.

Below are Runway's tiers, Sume's plan limits, and how to plan around each.

Runway's tiers

• Upgrade thresholds as listed on the page: $50, $100, $1,000 and $5,000 spent. Read the page to see which tier each one unlocks.
• The page says there is no RPM limit, and that throttled tasks queue in submission order.

Sume's gate

Sume reserves the estimated Sume USD amount at submit and captures it on success; failed jobs and failed admission release or refund the reservation. Concurrency is a separate, plan-based limit, and prepaid top-ups do not raise it.

Planning differences

• Runway: a spend ceiling you may hit mid-month, so watch spend against the tier cap.
• Sume: a balance check at submit, so watch the balance. 402 means the estimate could not be reserved. Upgrade the plan, wait for included Gen$, or submit something cheaper.
• Both: concurrency is a separate limit from money. On Sume, full concurrency alone is not an error; jobs wait as queued until the queue is full.
• On Sume's MCP you can add max_spend_usd to a paid call as a per-call ceiling, and dry_run to preview.

Handling 402

Do not retry a 402 in a loop. Top up or change the request, and use the same Idempotency-Key only for the exact same operation. Read the Sume generation admission docs for the full error table.