# Gateway Timeout (GATEWAY_TIMEOUT)

The upstream server did not respond within the allowed time.

## Common Causes

- **Slow upstream** — The backend server is taking too long to process the
  request.
- **Network issues** — Connectivity problems between Zuplo and the upstream
  server.
- **Large payloads** — The request or response body is very large and takes too
  long to transfer.
- **Upstream overload** — The backend server is under heavy load and unable to
  respond in time.

## How to Fix

### For API Consumers

- Retry the request after a short delay.
- Check if the upstream service is experiencing known issues.
- Reduce the request payload size if possible.

### For API Operators

- Verify the upstream server is healthy and responding.
- Check the URL Forward or URL Rewrite handler configuration to ensure the
  upstream URL is correct.
- Review upstream server logs for errors or slow queries.
- Consider increasing the timeout configuration if the upstream legitimately
  needs more time to respond.