How to access the request body when POSTing using Node.js and Express?

Question

Starting from express v4.16 there is no need to require any additional modules, just use the built-in JSON middleware:

app.use(express.json())

Like this:

const express = require('express')

app.use(express.json())    // <==== parse request body as JSON

app.listen(8080)

app.post('/test', (req, res) => {
  res.json({requestBody: req.body})  // <==== req.body will be a parsed JSON object
})

Note - body-parser, on which this depends, is already included with express.

Also don't forget to send the header Content-Type: application/json

Express 4.0 and above:

$ npm install --save body-parser

And then in your node app:

const bodyParser = require('body-parser');
app.use(bodyParser);

---

Express 3.0 and below:

Try passing this in your cURL call:

--header "Content-Type: application/json"

and making sure your data is in JSON format:

{"user":"someone"}

Also, you can use console.dir in your node.js code to see the data inside the object as in the following example:

var express = require('express');
var app = express.createServer();

app.use(express.bodyParser());

app.post('/', function(req, res){
    console.dir(req.body);
    res.send("test");
}); 

app.listen(3000);

This other question might also help: How to receive JSON in express node.js POST request?

If you don't want to use the bodyParser check out this other question: https://stackoverflow.com/a/9920700/446681

As of Express 4, the following code appears to do the trick. Note that you'll need to install body-parser using npm.

var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser.urlencoded({ extended: false }));


app.listen(8888);

app.post('/update', function(req, res) {
    console.log(req.body); // the posted data
});

For 2019, you don't need to install body-parser.

You can use:

var express = require('express');
var app = express();
app.use(express.json())
app.use(express.urlencoded({extended: true}))
app.listen(8888);
app.post('/update', function(req, res) {
    console.log(req.body); // the posted data
});

var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json())

var port = 9000;

app.post('/post/data', function(req, res) {
    console.log('receiving data...');
    console.log('body is ',req.body);
    res.send(req.body);
});

// start the server
app.listen(port);
console.log('Server started! At http://localhost:' + port);

This will help you. I assume you are sending body in json.

You should not use body-parser it is deprecated. Try this instead

const express = require('express')
const app = express()

app.use(express.json()) //Notice express.json middleware

The app.use() function is used to mount the specified middleware function(s) at the path which is being specified. It is mostly used to set up middleware for your application.

Now to access the body just do the following

app.post('/', (req, res) => {
  console.log(req.body)
})

This can be achieved without body-parser dependency as well, listen to request:data and request:end and return the response on end of request, refer below code sample. ref:https://nodejs.org/en/docs/guides/anatomy-of-an-http-transaction/#request-body

var express = require('express');
var app = express.createServer(express.logger());

app.post('/', function(request, response) {

    // push the data to body
    var body = [];
    request.on('data', (chunk) => {
      body.push(chunk);
    }).on('end', () => {
      // on end of data, perform necessary action
      body = Buffer.concat(body).toString();
      response.write(request.body.user);
      response.end();
    });
});