# RequestTimeoutException

**Kind:** Class

**Source:** [`packages/common/exceptions/request-timeout.exception.ts`](https://github.com/nestjs/nest/blob/master/packages/common/exceptions/request-timeout.exception.ts#L11)

**Part of:** [Common](subsystem-packages-common)

Defines an HTTP exception for *Request Timeout* type errors.

`RequestTimeoutException` represents an HTTP 408 Request Timeout error. Use it when a client request exceeds an allowed processing or response time, allowing NestJS exception filters to return a standardized timeout response.

**Extends:** `HttpException`

## Diagram

```mermaid
graph LR
  Client[HTTP Client] --> Controller[Controller / Service]
  Controller -->|Request exceeds time limit| Timeout[RequestTimeoutException]
  Timeout --> Filter[NestJS Exception Filter]
  Filter -->|HTTP 408 Request Timeout| Client
```

## Usage

```ts
import { Controller, Get, RequestTimeoutException } from '@nestjs/common';

@Controller('reports')
export class ReportsController {
  @Get()
  async generateReport() {
    const completedInTime = false;

    if (!completedInTime) {
      throw new RequestTimeoutException(
        'Report generation exceeded the allowed request time.',
      );
    }

    return { status: 'complete' };
  }
}
```

## AI Coding Instructions

- Throw `RequestTimeoutException` when the request cannot complete within an expected server-side time limit.
- Prefer this exception over generic `HttpException` when the appropriate HTTP response is `408 Request Timeout`.
- Include a clear, client-safe error message; avoid exposing internal timing, infrastructure, or dependency details.
- Let NestJS's built-in exception handling serialize the exception unless the application uses a custom global exception filter.
- For long-running work, consider asynchronous job processing or background queues instead of repeatedly extending request timeouts.

## Used by

1 reference from 1 file. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

### Imported by (1)

- `DisconnectedClientController` — `integration/microservices/src/disconnected.controller.ts`:12