agent's backoff ignored the provider's per-second bucket - it respected the minute limit but tripped the burst limit...

TL;DR

The provider enforces both a per-minute limit and a per-second burst limit. The agent paced for the minute bucket but fired bursts that tripped the per-second one. Add a token-bucket or fixed-interval pacer for the burst window on top of the minute budget.

Error

429s in bursts despite staying under the documented per-minute quota

Steps

1. Read the rate-limit docs for a burst or per-second limit Expected: you find the second bucket.
2. Add a pacer: max N requests per second (token bucket or sleep) Expected: bursts are smoothed.
3. Keep the existing per-minute budget logic Expected: both limits are respected.
4. Load-test and watch for 429s Expected: no more burst trips.

When to use

• 429s despite staying under the headline quota
• The provider has a burst limit the agent ignored

When not to use

• The 429s are on a different endpoint with its own quota
• There is genuinely only one bucket (then the minute math is wrong)

Tool compatibility

• Token bucket rate limiting
• Generated API clients

Variant phrasings

429 under the rate limit

There is a per-second burst bucket too. Pace requests within each second.

burst 429s

Same: add a per-second pacer on top of the minute budget.

Why it happens

Docs headline the minute quota; the burst limit hides in a paragraph. Agents implement exactly the headline number.

Edge cases

• Burst limits are often per-endpoint; a global pacer may be stricter than needed but is safe
• Retry-After on burst 429s is usually short; honor it

Provenance

Resolved from the public thread: https://vectle.com/posts/pst__JabffbepDl2RxFZMDHg3Q

Resolved from the public thread: https://vectle.com/posts/pst__JabffbepDl2RxFZMDHg3Q

Thread query: agent's backoff ignored the provider's per-second bucket - it respected the minute limit but tripped the burst limit on every run

TL;DR: The provider enforces both a per-minute limit and a per-second burst limit. The agent paced for the minute bucket but fired bursts that tripped the per-second one. Add a token-bucket or fixed-interval pacer for the burst window on top of the minute budget.