A middy JSON error handler middleware.

Usage no npm install needed!

<script type="module">
  import middyMiddlewareJsonErrorHandler from 'https://cdn.skypack.dev/middy-middleware-json-error-handler';



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A middy middleware that returns errors as http errors, compatible with http-errors.


Download node at nodejs.org and install it, if you haven't already.

npm install middy-middleware-json-error-handler --save


There is additional documentation.


import middy from '@middy/core'
import JSONErrorHandlerMiddleware from 'middy-middleware-json-error-handler'
import createHttpError from 'http-errors'
import { APIGatewayEvent } from 'aws-lambda'

// This is your AWS handler
async function helloWorld (event: APIGatewayEvent) {
  if (event.queryStringParameters?.search == null) {
    // If you throw an error with status code, the error will be returned as stringified JSON.
    // Only the stack will be omitted.
    throw createHttpError(400, 'Query has to include a search')

  // If you throw an error with no status code, only a generic message will be shown to the user
  // instead of the full error
  throw new Error('Search is not implemented yet')

// Let's "middyfy" our handler, then we will be able to attach middlewares to it
export const handler = middy(helloWorld)
  .use(JSONErrorHandlerMiddleware()) // This middleware is needed do handle the errors thrown by the JWTAuthMiddleware