Skip to main content


This middleware automatically parses HTTP requests with a JSON body and converts the body into an object. Also handles gracefully broken JSON as UnprocessableEntity (422 errors) if used in combination with httpErrorHandler.

It can also be used in combination with validator as a prior step to normalize the event body input as an object so that the content can be validated.

If the body has been parsed as JSON, you can access the original body (e.g. for webhook signature validation) through the request.event.rawBody.


To install this middleware you can use NPM:

npm install --save @middy/http-json-body-parser


  • reviver (function) (optional): A reviver parameter may be passed which will be used JSON.parseing the body.

Sample usage

import middy from '@middy/core'
import httpHeaderNormalizer from '@middy/http-header-normalizer'
import httpJsonBodyParser from '@middy/http-json-body-parser'

const handler = middy((event, context) => {
return {}


// invokes the handler
const event = {
headers: {
'Content-Type': 'application/json'
// It is important that the request has the proper content type.
body: JSON.stringify({foo: 'bar'})
handler(event, {}, (_, body) => {,{foo: 'bar'})