> For the complete documentation index, see [llms.txt](https://docs.appfarm.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.appfarm.io/166/throw-exception.md).

# Throw exception

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This page describes release **166 (Early)**. For the current Standard version, see [Throw exception](https://docs.appfarm.io/library/action-nodes/throw-exception).
{% endhint %}

The Throw exception action node stops the Action with a custom error. [Catch exception](https://docs.appfarm.io/library/action-nodes/catch-exception) can catch and handle it, so you can control what happens when something goes wrong.

If no Catch exception handles the error, the Action stops at this node.

### Usage

* **Data validation:** Stop when data from a form or an external endpoint is invalid.
* **Clear error messages:** Give the user a message that says what went wrong and what to do.
* **Logging and debugging:** Use the exception code to tell error types apart, for example in an [event log](https://docs.appfarm.io/how-to/logic-and-flow/event-log-design).

### Properties

<table><thead><tr><th width="213">Property</th><th>Description</th></tr></thead><tbody><tr><td><strong>Message</strong></td><td>Description of what went wrong. If the exception is not caught in a run triggered through an endpoint, the message is included as <code>message</code> in the error response.</td></tr><tr><td><strong>Exception code</strong></td><td>Identifies the kind of error, for example <code>ORDER_NOT_FOUND</code>. A Catch exception node can target this code to catch exactly this exception and let others pass through. If the exception is not caught in a run triggered through an endpoint, the code is included in the error response. It does not change the HTTP status code; set <strong>Response code</strong> for that.</td></tr><tr><td><strong>Response code</strong></td><td><em>Shown in Services and in Flows with an endpoint trigger.</em><br><br>The HTTP status code the endpoint responds with if the exception is not caught, for example <code>404 Not Found</code>. Only applies to runs triggered through an endpoint; other triggers ignore it. Default is <code>500 Internal Server Error</code>.</td></tr></tbody></table>


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