# 45780: Operation failed: too many concurrent API requests

Log Type: APPLICATION

Log Level: WARNING

## Description

This warning occurs when your account sends too many concurrent requests for the Flex API operation you are calling. Flex endpoints return `HTTP 429` when rate limits are exceeded, and a request that receives `HTTP 429` was not processed.

### Possible causes

* Your application sent too many concurrent requests to the same Flex endpoint.
* A burst of traffic exceeded the rate limit for the Flex endpoint you are using.
* Your client is retrying too quickly after a throttled request.
* Your integration is polling Flex resources too frequently instead of reducing repeated `GET` requests.
* For Flex Conversations, you exceeded an endpoint-specific limit such as the Interactions API limit of 20 requests per second per endpoint per account or the Flex Webchat orchestrator limit of 5 requests per second.

### Possible solutions

* Wait briefly and retry the request.
* Implement retries with exponential backoff so your client does not immediately send another burst of requests.
* Throttle or queue requests in your application to reduce concurrent calls to the Twilio API.
* Review the rate limits for the specific Flex endpoints your integration uses and keep traffic below those limits.
* Reduce unnecessary polling. Use webhooks or store the data you need on your own servers when possible so you do not repeatedly fetch the same resources.
* Monitor the `Twilio-Concurrent-Requests` and `Twilio-Request-Duration` response headers so you can see when request volume is approaching account concurrency limits.
* If you still hit this warning after reducing traffic and adding backoff, contact Support with your use case and request details.

#### Additional resources

* [API best practices](/docs/usage/rest-api-best-practices)
* [File Attachments and API Limits](/docs/flex/developer/conversations/limits)
* [Twilio API response Error 429 "Too Many Requests"](https://help.twilio.com/articles/360044308153-Twilio-API-response-Error-429-Too-Many-Requests-)