# NestExpressBodyParserOptions

**Kind:** Interface

**Source:** [`packages/platform-express/interfaces/nest-express-body-parser-options.interface.ts`](https://github.com/nestjs/nest/blob/master/packages/platform-express/interfaces/nest-express-body-parser-options.interface.ts#L8)

**Part of:** [Platform Express](subsystem-packages-platform-express)

Type alias to keep compatibility with

`NestExpressBodyParserOptions` defines the supported configuration for body parsing in the NestJS Express platform. It mirrors the relevant Express/body-parser options to preserve compatibility when configuring how incoming request bodies are inflated, size-limited, and matched by content type.

## Properties

| Property | Type |
|---|---|
| `inflate` | `boolean | undefined` |
| `limit` | `number | string | undefined` |
| `type` | `string | string[] | ((req: IncomingMessage) => any) | undefined` |

## Diagram

```mermaid
graph LR
  A[NestExpressBodyParserOptions] --> B[inflate]
  A --> C[limit]
  A --> D[type]

  B --> B1[Enable or disable compressed body inflation]
  C --> C1[Maximum accepted request body size]
  D --> D1[Content type string, array, or request predicate]

  A --> E[Express body parser configuration]
```

## Usage

```ts
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import type { NestExpressBodyParserOptions } from '@nestjs/platform-express';

async function bootstrap() {
  const bodyParserOptions: NestExpressBodyParserOptions = {
    inflate: true,
    limit: '2mb',
    type: ['application/json', 'application/*+json'],
  };

  const app = await NestFactory.create(AppModule, {
    bodyParser: false,
  });

  app.useBodyParser('json', bodyParserOptions);

  await app.listen(3000);
}

bootstrap();
```

## AI Coding Instructions

- Use this interface when passing body-parser-compatible options to Nest's Express platform APIs, such as `app.useBodyParser()`.
- Set `limit` to a conservative value (for example, `'1mb'` or `'2mb'`) to reduce the risk of oversized request payloads.
- Use `type` to restrict parsing to expected content types; a predicate receives the Node.js `IncomingMessage`.
- Keep `inflate` enabled unless the application explicitly needs to reject compressed request bodies.
- Do not assume these options apply to every parser type; ensure the selected parser and Express integration support the configured behavior.