A realtime communication framework

npm install largemouth
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LargeMouth an open BAAS Build Status

An open BAAS with a similar API to firebase.


Firebase is a Backend As A Service (BAAS) which allows developers to quickly build applications without worrying about the communication layer between the server and client. Firebase is awesome but the backend remains entirely proprietary. LargeMouth / SmallMouth attempt to recreate the Firebase api as an open-source project. Idealy a Firebase app could be easily moved to SmallMouth and vice versa.

LargeMouth is built on top of and NodeJS.


npm install -g largemouth

Boot Options

Change the server port (3000 default):

largemouth -p 3000

Change the location of the configuration file (working directory largemouth.js default):

largemouth -c ../myConfig.js


SmallMouth is the client side library.


Server configuration is defined within a JavaScript file by default located within the working directory of where LargeMouth is run. The config file allows the following:

  • Permissions - The security permission definition.
  • Custom events - Define custom events which the server will listen for.

An example config file:

module.exports = function(largemouth) {

    // Optionally define the server port here (commandline will override this value)
    largemouth.port = 3000;[[

    // The custom event will be passed a request object which will contain
    // any data sent from the client as well as the actual socket instance,
    // allowing you to respond to the client with custom events through socket.emit['someEvent'] = function(req, socket) {
            console.log('hi', req);

    // Only basic rules implemented, no expressions/variables
    largemouth.rules = {
        ".read": true,
        ".write": false,
        "chats": {
            ".read": true,
            ".write": true

Release notes

  • 0.3.0 - Basic permissions and rules implemented. Fully implemented the resource.remove() method.
  • 0.2.4 - Load the config file and define custom events.
  • 0.2.0 - Don't send down entire datasets to notify clients of changes, rather send down what changed and allow the client to resolve the data.
  • 0.1.0 - Minimal portion of the Firebase API supported.

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