---
title: ratelimit.concurrent_cap_reached
description: The workspace already has 10 call requests in flight; retry after one second.
summary: >-
  Returned with 429 and Retry-After of 1 when a workspace already has 10
  requests in flight on the call routes. The refused request places no call and
  debits nothing.
date: 2026-11-11T00:00:00.000Z
type: error
---


`ratelimit.concurrent_cap_reached` is returned on the call routes when the workspace already has 10 requests in flight. The limit is shared by every API key and member of the workspace.

## Cause

Ten requests on the call routes, such as `POST /v1/calls` or a live-control `GET /v1/calls/{call_id}/control/events`, were accepted and had not finished when this one arrived.

## Resolution

Wait the number of seconds in the `Retry-After` header (one second) and send the same request again. Use the same `Idempotency-Key`. A refused request places no call and debits nothing. If you send many calls at once, keep fewer than 10 requests in flight from your side.

## Example response

```json
{
  "error": {
    "code": "ratelimit.concurrent_cap_reached",
    "message": "workspace concurrent call limit of 10 reached",
    "request_id": "req_01900000abc"
  }
}
```

## Next steps

- See [Rate limits](/developers/concepts/rate-limits) for every limit and the routes it covers.