# `GATEWAY_TIMEOUT` The answer took too long

Source: https://checkslip.com/en/problems/gateway-timeout

- **HTTP status**: `504`
- **Credit**: Not settled yet

## Meaning

We could not answer within 30 seconds. The request may still finish, so its result, and whether a credit was used, are not known yet.

## Cause

Handling this request took longer than 30 seconds.

## Fix

For a slip lookup (`POST /api/slips/lookup`), first read its result with `GET /api/slips/{request_id}` (request_id is this answer's `X-Request-Id`), or retry with the same `Idempotency-Key`, which is never charged twice. While the first request still runs you get `409 IDEMPOTENCY_IN_FLIGHT`, so wait and try again. Once it finishes you get its result (same request_id). A retry without the same key counts as a new request.

## Example response

```
{
  "type": "https://checkslip.com/problems/gateway-timeout",
  "title": "The answer took too long",
  "status": 504,
  "instance": "01a18600-0000-7000-8000-000000000000",
  "code": "GATEWAY_TIMEOUT"
}
```