The eps web framework
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EPS Web Framework

An oppinionated reactive server side web framework for node.js based off of RxJS.


Clone the repo to a destination of your choice:

git clone

Install the dependencies:

npm install

Fire the bass cannon:

npm start

Pick up your loot at http://localhost:3000

The basics

EPS is part framework part lego kit. It gives you lots of powerful components to snap together and you can choose to create or replace whatever components you see fit.

A basic setup creates an eps conduit from a function that takes a RxHttpServer and applies a series of root middleware to the requests observable returning the final composition. A conduit will internally and automatically spin off and manage 1 worker node per CPU core. If a worker dies for whatever reason the master process will spawn a new one.

This basic setup typically lives in your src/main.js file and will look something like the following:

var path                = require("path");
var eps                 = require("eps");
var serviceContainer    = require("./services/container");
var requestLogger       = require("./middleware/root/request-logger");
var less                = require("./middleware/root/less");
var staticFiles         = require("./middleware/root/static-files");
var services            = require("./middleware/root/services");
var cookieReader        = require("./middleware/root/cookie/reader");
var cookieWriter        = require("./middleware/root/cookie/writer");
var flashSessionReader  = require("./middleware/root/flash-session/reader");
var flashSessionWriter  = require("./middleware/root/flash-session/writer");
var signedSessionReader = require("./middleware/root/signed-session/reader");
var signedSessionWriter = require("./middleware/root/signed-session/writer");
var router              = require("./middleware/root/router");
var WorkerOnlineAction  = require("./models/actions/worker/online");
var WorkerDiedAction    = require("./models/actions/worker/died");

var conduit = eps(function(server) {
    var lessPath   = path.join(__dirname, "public/css/main.less");
    var publicPath = path.join(__dirname, "public");
    return server
        .flatMap(less("/public/css/main.css", lessPath))
        .flatMap(staticFiles("/public", publicPath))
        .flatMap(signedSessionReader("Why is a raven like a writing desk?"))
        .flatMap(signedSessionWriter("Why is a raven like a writing desk?"))

conduit.workerUp.subscribe(function(cluster) {
    serviceContainer("logger").subscribe(function(logger) { WorkerOnlineAction(cluster));

conduit.workerDown.subscribe(function(data) {
    serviceContainer("logger").subscribe(function(logger) {
        logger.error(new WorkerDiedAction(data.worker));


Likewise, each controller is a composition of components. The actual controller action is preceded by an optional and custom preAction pipeline and followed by another optional and custom postAction pipeline.

A simple example that makes sure a user is unauthenticated and grabs the template service in the preAction pipeline and does etag cache checking in the postAction pipeline would look something like this:

var Rx              = require("rx");
var handler         = require("rx-request-handler");
var OkResponse      = require("responses/response/ok");
var response        = require("../util/response");
var unauthenticated = require("../middleware/controller/pre/unauthenticated");
var requireService  = require("../middleware/controller/pre/require-service");
var etagHit         = require("../middleware/controller/post/etag-hit");
var etagResponse    = require("../middleware/controller/post/etag-response");

module.exports = handler({

    preAction: function(observable) {
        return observable

    action: function(data) {
        return response(OkResponse, data, function() {

    postAction: function(observables) {
        return observables