A very simple json-header-and-body protocol
Latest commit 4e00515 May 20, 2015 @isaacs v1.1.1
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example examples Mar 2, 2013
test a test with tcp Mar 2, 2013
LICENSE isc license May 20, 2015
README.md readme Mar 2, 2013
incoming.js fix for new transform api Mar 11, 2013
index.js codes Mar 2, 2013
outgoing.js fix for new transform api Mar 11, 2013
package.json v1.1.1 May 20, 2015



A very simple header-and-body protocol.

Originally written as an example in a Node API doc.


var sp = require('simple-protocol');
var Incoming = sp.Incoming;
var Outgoing = sp.Outgoing;

// throw some tcp in there, just for funsies
// Note that we have to use allowHalfOpen, because we're not
// explicitly managing the sockets, and we want to not close
// when we get a FIN from the client.
// In a real live environment, you'd probably want a client that can
// pool and reuse connections, do keepAlive, etc., and you'd then
// want to turn off allowHalfOpen, because the server is not
// interested in what the client has to say after it's finished
// sending the response.
require('net').createServer({ allowHalfOpen: true }, function(sock) {
  var req = new Incoming();
  var res = new Outgoing();

  req.on('header', function(h) {
    console.log('SERVER header', h);

  req.on('data', function(chunk) {
    console.log('SERVER message %j', chunk.toString());

  req.on('end', function() {
    console.log('SERVER end');
    res.header = { well: 'that was fun' };
    res.write('ok, ');
    res.end('goodbye, now');

}).listen(1337, function() {
  var sock = require('net').connect(1337);
  sock.allowHalfOpen = true;
  sock.on('connect', function() {
    var req = new Outgoing();
    var res = new Incoming();

    req.header = { hello: 'alice', this: 'is bob' };

    res.on('header', function(h) {
      console.log('CLIENT header', h);
    res.on('data', function(chunk) {
      console.log('CLIENT message %j', chunk.toString());
    res.on('end', function() {
      console.log('CLIENT end');

    req.write('this is body chunks');
    req.write('.  and it will stream and stream\n');
    req.end('because there is no I in example.\n');

And the output goes like:

SERVER header { hello: 'alice', this: 'is bob' }
SERVER message "this is body chunks.  and it will stream and stream\nbecause there is no I in example.\n"
CLIENT header { well: 'that was fun' }
CLIENT message "ok, goodbye, now"


If you want to use this with node v0.8 and before, you'll need to also install the readable-stream module. It's not added as a dependency, because the future is larger than the past.