HTTP 429 · type rate_limit_error · retryable true

defaultMessage Daily send quota exceeded.

plan_quota_exceeded

Workspace or API-key daily message quota is exhausted.

What to do

1. Read Retry-After (seconds until UTC midnight) and back off until then.
2. Spread volume across the day; broadcasts count one per recipient, not one per HTTP call.
3. Upgrade plan or raise key limits in the dashboard if traffic is legitimate.
4. Avoid tight retry loops — each successful accept consumes quota again.
5. For broadcasts that failed to enqueue after INCR, Tecron attempts DECRBY; still treat 429 as hard stop for new accepts.