---
title: "Why does my Signals custom event URL return 'Number of API requests exceeded the threshold limit' (TOO_MANY_REQUESTS)?"
url: https://docs.catalyst.zoho.com/en/faq/signals/custom-event-url-too-many-requests/
description: "This happens when your application sends more than 500 requests per minute to the REST API URL of a custom event in Catalyst Signals. Above that threshold, the …"
last_updated: 2026-11-13T05:00:22Z
service: Signals
type: faq
---

This happens when your application sends more than 500 requests per minute to the REST API URL of a custom event in Catalyst Signals. Above that threshold, the URL is locked for the next 60 seconds, so requests sent during that time are refused.

1. Send events in batches: one call can carry an array of up to 25 events and 256 KB, with each event up to 64 KB.
2. Spread bursts over time, or queue events in your application and send them at a steady rate.
3. When a request is refused, wait for the lock to end before you retry.
4. If your volume still needs more than 500 requests per minute, contact Catalyst support with your use case, the peak rate per minute, the expected requests per day and the size of each request.

Refer to the [Custom Publishers help page](https://docs.catalyst.zoho.com/en/signals/help/publishers/create-publisher/custom-publishers/) for details.