concurrency_limit_exceeded

HTTP 429 · retryable

The submitting account is at its concurrent-job cap for the requested provider. The platform enforces caps both globally (per-provider) and per-account (per-plan); this code signals the per-account ceiling.

Distinct from rate_limit_exceeded (per-key request budget) and quota_exceeded (insufficient credits).

How to fix

• Wait the number of seconds reported in the Retry-After response header, then resubmit.
• Reduce in-flight submissions for the affected provider — finish or cancel queued jobs before adding more.
• Stagger heavy batches across time, or split them across multiple providers if your job mix permits.

v1 behaviour

The plugin API in v1 does not pre-check concurrency at submission time. Caps are enforced at runtime by cg-worker's ConcurrencyService: jobs above the cap remain queued (status: 'pending') and are picked up automatically as slots free up. This error code is reserved for a future pre-submit probe and for platform-side soft limits we may add to plans.

If you observe genuinely-stalled jobs, check GET /jobs/{id} — status: 'pending' with a steadily-increasing attempt_count is normal queue behaviour, not a concurrency rejection.