# Unknown Error (UNKNOWN_ERROR)

This is an unhandled error in the Zuplo runtime. The error does not match any
known error category.

## Common scenarios

- **Unhandled exception in custom code** - A request handler or policy throws an
  unexpected error that is not caught by a try/catch block.
- **Unexpected runtime behavior** - An edge case in the runtime produces an
  error that is not categorized.
- **Third-party service failures** - An external service call fails in an
  unexpected way that is not handled by the code.

## How to debug

1. Check the runtime logs for the full error message and stack trace.
2. Look for the specific request ID in the logs to find related log entries.
3. Review recent code changes for potential unhandled error paths.
4. Add try/catch blocks around external service calls and other error-prone code
   to handle errors gracefully.

## What to include when contacting support

If the error persists and you cannot identify the cause, contact
[Zuplo support](../articles/support.mdx) with the following information:

- The **request ID** from the error response.
- The **timestamp** of when the error occurred.
- The **route path** and **HTTP method** of the failing request.
- Any **recent changes** to the project code or configuration.
- Relevant **log entries** from around the time of the error.

:::tip

Adding structured logging to request handlers makes it easier to diagnose
unknown errors. See [Logging](../articles/logging.mdx) for details on
configuring log output.

:::