Primacron is a high level abstraction build on top of Primus

npm install primacron
4 downloads in the last month


Primacron is a small API wrapper for Engine.IO that takes care of our "scaling" and multi server logic. This keeps our services as light as possible so we can focus on our business logic instead of other issues.


The module can be installed through npm:

npm install --save primacron

Creating your first server

The module exposes it's constructor as primary interface. This makes it easy to extend and to initialise:

var Primacron = require('primacron')
  , redis = require('redis');

var server = new Primacron(redis.createClient(), { options })

Or if want some alternate syntax you could use:

var primacron = require('primacron')
  , redis = require('redis');

var server = primacron.createServer(redis, { options });

And even:

var primacron = require('primacron')
  , redis = require('redis');

var server = primacron(redis.createClient(), { options })

Once you've created your server instance, it needs to listen to port number. This works just like a regular net.Server instance using a .listen method. All the arguments that are supplied here are directly proxied to the HTTP server.

server.listen(8080, function () {
  // listening


The server exposes the endpoint as /stream/ by default path. The server assumes that all connections will be made with an account parameter in the query string.

Error events

To be a as module agnostic as possible, we don't log errors or broken code instead we emit namespaced error::<errtype> events. These events can be listend on by the applications and decide if they want to log it.

The following error events are emitted:

key, value
We failed to store our connection in the provided redis database. The connection cannot be found by other node processes. So no broadcasting would be possible. This should be seen as a critical error.
key, value
We failed to remove the connection in the provided redis database. While it should automatically expire it could result in false positives and pointless broadcasts to the given server. This isn't a critical error but could indicate database failure.
We failed to parse the received message by our decoder. This shouldn't happen ever, if it does you could assume that some is trying to crash the server or to find back doors. This should be seen a critical error.
We received a JSON document, but it wasn't an Object.. Someone is tyring to do fishy things with the server and action should be taken.. Cause as above.
event, error
The received message event was invalid.
npm loves you