UnsupportedMediaTypeException

Kind: Class

Source: packages/common/exceptions/unsupported-media-type.exception.ts

Part of: Common

Defines an HTTP exception for Unsupported Media Type type errors.

UnsupportedMediaTypeException represents an HTTP 415 error, indicating that the server cannot process a request because its Content-Type is unsupported. It is typically thrown by controllers, guards, or middleware during request validation so NestJS can return a standardized HTTP error response.

Extends: HttpException

Diagram

mermaid
graph LR
  A[Client request] --> B[Content-Type validation]
  B -->|Supported media type| C[Controller handler]
  B -->|Unsupported media type| D[UnsupportedMediaTypeException]
  D --> E[HTTP 415 response]

Usage

ts
import {
  Controller,
  Post,
  Headers,
  UnsupportedMediaTypeException,
} from '@nestjs/common';

@Controller('uploads')
export class UploadController {
  @Post()
  upload(@Headers('content-type') contentType?: string) {
    if (!contentType?.startsWith('image/png')) {
      throw new UnsupportedMediaTypeException(
        'Only image/png uploads are supported.',
      );
    }

    return { message: 'Upload accepted' };
  }
}

AI Coding Instructions

• Throw this exception when validation fails specifically because the request media type or Content-Type header is unsupported.
• Prefer HTTP 415 over BadRequestException when the request body format is valid but its declared media type is not accepted.
• Validate media types with startsWith() when parameters such as charset or multipart boundaries may be present.
• Provide a clear error message describing the accepted media types for API consumers.
• Use NestJS exception filters or the default exception handling pipeline rather than manually constructing HTTP 415 responses.