What does the VARTA error `concurrency_limit_exceeded` mean?

HTTP status: 429  ·  Type: rate_limit_error

What it means

Reserved for a tenant or deployment with too many calls in flight at once.

What causes it

Cause not yet documented as a live /v1 path. The underlying concurrent-call cap exists (backend/app/security/abuse_guard/limiter.py) but today is wired only into an internal, non-/v1 endpoint; a /v1 caller who trips a concurrency limit currently receives rate_limit_exceeded instead.

What to do

Treat rate_limit_exceeded as covering this case for now.