> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zapier.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Troubleshoot throttles
## Throttling by your API
### Constraint
Your API has request limits.
### Errors user will see if constraint is hit
* If a trigger, user will receive an email with an error message about the trigger error
* If an action, user will see an error in Zap history
### Best practice
Add a specific `Retry-After` header to your 429 response, or specify a timed delay in your error response using a special `ThrottledError`. Instead of a user's Zap erroring and halting, the request will be retried at the specified time.
More on the retry [here](https://github.com/zapier/zapier-platform/blob/main/packages/cli/README.md#handling-throttled-requests). The user will see a [Waiting/Scheduled](https://help.zapier.com/hc/en-us/articles/20505304170637-Review-Zap-run-statuses) message in Zap history instead of an error while the limit is still in place.
{" "}
{" "}
If implementing a `ThrottledError`, you could consider implementing a jitter for handling 429 errors, that could look something like this to randomize the frequency of the retries as well:
`throw new z.errors.ThrottledError('message here', 60 + Math.floor(Math.random() * 60))`
Keep in mind that adding custom error handling with `ThrottledError` would likely require a [new integration version](/integrations/manage/versions), whereas adding to the headers could be implemented on your API's end.
## Webhook throttles by Zapier
### Constraint
Zapier's current webhook limits are [here](https://help.zapier.com/hc/en-us/articles/8496181445261#h_01H91ED0PQ56S166BSB7MJNZNT). A 429 response is returned if your integration exceeds these limits in number of webhooks sent to Zapier.
### Errors user will see if constraint is hit
* User will receive an email with an error message about the trigger error
### Best practice
You should support a retry/back-off schedule to make sure the data is eventually received.
## Polling trigger throttles by Zapier
### Constraint
There is a default limit of 100 new items recognized per poll after deduplication. More on that [here](https://help.zapier.com/hc/en-us/articles/8496181445261-Rate-limits-and-throttling-in-Zapier#h_01H91ED0PQ1HK1G1YFTZ9NSPRN).
### Errors user will see if constraint is hit
* The user will receive an email about held Zap runs, as well as a banner with the same information in their Zap history.
### Best practice
If your trigger will be returning > 100 new records consistently, consider converting your trigger to be REST Hook based. Webhook limits are higher (up to 10,000 requests in a 5 minute period).
***
*Need help? [Tell us about your problem](https://developer.zapier.com/contact) and we'll connect you with the right resource or contact support.*