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Get and validate the raw body of a readable stream.


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Gets the entire buffer of a stream either as a Buffer or a string. Validates the stream's length against an expected length and maximum limit. Ideal for parsing request bodies.


var getRawBody = require('raw-body')

getRawBody(stream, [options], [callback])

Returns a promise if no callback specified and global Promise exists.


  • length - The length of the stream. If the contents of the stream do not add up to this length, an 400 error code is returned.
  • limit - The byte limit of the body. This is the number of bytes or any string format supported by bytes, for example 1000, '500kb' or '3mb'. If the body ends up being larger than this limit, a 413 error code is returned.
  • encoding - The encoding to use to decode the body into a string. By default, a Buffer instance will be returned when no encoding is specified. Most likely, you want utf-8, so setting encoding to true will decode as utf-8. You can use any type of encoding supported by iconv-lite.

You can also pass a string in place of options to just specify the encoding.

callback(err, res):

  • err - the following attributes will be defined if applicable:

    • limit - the limit in bytes
    • length and expected - the expected length of the stream
    • received - the received bytes
    • encoding - the invalid encoding
    • status and statusCode - the corresponding status code for the error
    • type - either entity.too.large, request.aborted, request.size.invalid, stream.encoding.set, or encoding.unsupported
  • res - the result, either as a String if an encoding was set or a Buffer otherwise.

If an error occurs, the stream will be paused, everything unpiped, and you are responsible for correctly disposing the stream. For HTTP requests, no handling is required if you send a response. For streams that use file descriptors, you should stream.destroy() or stream.close() to prevent leaks.


Simple Express example

var contentType = require('content-type')
var express = require('express')
var getRawBody = require('raw-body')
var app = express()
app.use(function (req, res, next) {
  getRawBody(req, {
    length: req.headers['content-length'],
    limit: '1mb',
    encoding: contentType.parse(req).parameters.charset
  }, function (err, string) {
    if (err) return next(err)
    req.text = string
// now access req.text 

Simple Koa example

var contentType = require('content-type')
var getRawBody = require('raw-body')
var koa = require('koa')
var app = koa()
app.use(function * (next) {
  this.text = yield getRawBody(this.req, {
    length: this.req.headers['content-length'],
    limit: '1mb',
    encoding: contentType.parse(this.req).parameters.charset
  yield next
// now access this.text 

Using as a promise

To use this library as a promise, simply omit the callback and a promise is returned, provided that a global Promise is defined.

var getRawBody = require('raw-body')
var http = require('http')
var server = http.createServer(function (req, res) {
  .then(function (buf) {
    res.statusCode = 200
    res.end(buf.length + ' bytes submitted')
  .catch(function (err) {
    res.statusCode = 500