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Electrode Fastify Server

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This is an imaginatively named, configurable web server using Fastify atop Node.js.

The aim is to provide a standardized node web server that can be used to serve your web application without the need for duplicating from another example, or starting from scratch.

The intention is that you will extend via configuration, such that this provides the baseline functionality of a Fastify web server, and within your own application you will add on the features, logic, etc unique to your situation.

This module requires Node v14.x.x+.

Table Of Contents


npm i --save @xarc/fastify-server


Electrode Server comes with enough defaults such that you can spin up a Fastify server at http://localhost:3000 with one call:


Of course that doesn't do much but getting a 404 response from http://localhost:3000. To handle your routes, you should create a Fastify plugin to install your handlers. See below for configuration options on how to register your plugin through @xarc/fastify-server.

Hello World Example

Here is an example with a default route to return a Hello World string for http://localhost:3000.

Through a plugin:

  plugins: {
    routes: {
      register: async instance => {
          method: "GET",
          path: "/",
          handler: async () => "Hello World"

Using deferStart flag to get a server that hasn't started yet:

// fastify doesn't allow adding routes after server started
// so need to set deferStart flag true to be able to add a route and then start the server.
require("@xarc/fastify-server")({ deferStart: true }).then(server => {
    method: "GET",
    path: "/",
    handler: async () => "Hello World"
  return server.start();


You can pass in a config object that controls every aspect of the Fastify server.

const config = {
  connection: {
    port: 9000,


However, for a more complex application, it's recommended that you use a config composer such as electrode-confippet to manage your app configuration.

Configuration Options

Sample of supported options:

const config = {
  server: {
    // options to be passed to fastify constructor
  connection: {
    // host, port etc
  plugins: {
    // specify fastify plugins to be registered
  listener: emitter => {
    // setup server startup event handlers
  deferStart: true, // don't start the server, you need to call server.start()
  electrode: {
    // options specific to Electrode such as logLevel

All properties are optional (if not present, the default values shown below will be used).

server.app.config is set to a object that's the combination of your config with @xarc/fastify-server's defaults applied.

server (Object)

  • Server options to pass to Fastify


  server: {
    app: {
      electrode: true;

connection (Object)

  • Connection to setup for the Fastify server. Contains connection details for the server.
  • If you want multiple connections, you can start multiple instances of @xarc/fastify-server


  connection: {
    host: process.env.HOST,
    address: process.env.HOST_IP || "",
    port: parseInt(process.env.PORT, 10) || 3000,
    routes: {
      cors: true

plugins (Object)

Default is just empty object:

  plugins: {

electrode (Object)

Configure electrode provided options.

  electrode: {
    eventTimeout: 5000, // milliseconds to wait for server start event listeners to return
  • eventTimeout - optional milliseconds to wait for your server start event listeners to return. default 10000. Set it to 0 or false to disable timeout completely.

listener (function)

  • A function to install event listeners for the electrode server startup lifecycle.

  • The following events are supported:

    • config-composed - All configurations have been composed into a single one
    • server-created - Fastify server created
    • plugins-sorted - Plugins processed and sorted by priority
    • plugins-registered - Plugins registered with Fastify
    • server-started - Server started
    • complete - Final step before returning

To receive events you must set config.listener before calling electrodeServer.

For example:

myConfig.listener = (emitter) => {
  emitter.on("server-created", (data, next) => {
    // do something
  • The data object will contain these: emitter, server, config, and plugins.

  • Depending on the stage some may not be present. For example, server is not available until server-created event and plugins is not available until plugins-sorted event.

  • These are async events so you have to take and call a next callback.

keepAliveTimeout (integer)

NodeJS defaults to 5 seconds keep-alive timeout. fastify-server defaults to 60 seconds timeout. If you want a custom timeout, use the keepAliveTimeout option (in milliseconds).

  "keepAliveTimeout": 60000


You can control how much output the Electrode Server logs to the console by setting the logLevel.

  • Levels are "info", "warn", "error", "none".
  • A level of "warn" means only warnning and error messages will be printed.
  • Default is "info"

For example, to suppress the banner that is shown when the server starts up:

Fastify server running at http://mypc:4000

set the logLevel to "warn" or "error":

  electrode: {
    logLevel: "warn";


To keep your environment specific configurations manageable, you can use electrode-confippet.

Once you have your config files setup according to the configuration files setup, you can simply pass the config object to electrode server.

const config = require("electrode-confippet").config;


Adding a Fastify plugin

You can have @xarc/fastify-server register any Fastify plugin that you want through your configuration file.

  plugins: {
    "<plugin-id>": {
      enable: true,
      options: {},
      register: (fastify, opts, done) => { done() }, // mutual exclusive with module
      module: "<plugin-module-name>",
      requireFromPath: process.cwd(),
      priority: 210,
      fastifyPluginDecorate: false

Plugin configs

  • <plugin-id> - ID for the plugin. Generally the module name for the plugin, which is used to load it for registration.
  • enable - optional if set to false then this plugin won't be registered. If it's not set then it's considered to be true.
  • options - optional Object that's passed to the plugin's register function.
  • register - optional The Fastify plugin function. Overrides module.
  • module - optional name of the module to load for the plugin instead of the <plugin-id>
  • requireFromPath - optional The path from which to call require to load the plugin module
  • priority - optional integer value to indicate the plugin's registration order
    • Lower value ones are register first
    • Default to Infinity if this field is missing or has no valid integer value (NaN) (string of number accepted)
  • fastifyPluginDecorate - optional fastify-server auto decorates your plugin with fastify-plugin - set this to false to disable this behavior. This can also be set to an object to use as options for fastify-plugin.

About Plugin Priority

Priority allows you to arrange plugins to be registered in an order you prefer. The plugins with lower priority values are registered first.

More about register and module

If you don't want to use <plugin-id> to load the module, then you can optionally specify one of the following:

  • register - if specified, then treat as the plugin's register function to pass to Fastify, overides module
  • module - Only used if register is not specified
    • If it's a string the used as the name module to require for registration.
    • It it's false then electrode server will not load any module.
    • You can specify a require-from-path for the module using an object.
          plugins: {
            myPlugin: {
              module: {
                requireFromPath: process.cwd(),
                name: "my-plugin-module"

Exporting your Fastify Plugin from a module

Electrode fastify server will try to find your Fastify Plugin from your module by looking through these fields:

  1. mod.fastifyPlugin
  2. mod.default.fastifyPlugin (ES6 Module)
  3. mod.plugin
  4. mod.default (ES6 Module)
  5. mod itself


  1. Exporting the plugin directly as the module:

CommonJS example:

module.exports = myPlugin;
module.exports.fastifyPlugin = myPlugin;

ES6 example:

export default myPlugin;
export fastifyPlugin;

With fastify-plugin:

const fastifyPlugin = require("fastify-plugin");
module.exports = fastifyPlugin(myPlugin, {
  name: "myPlugin"

More about requireFromPath

There are three places you can specify a path to call require from when loading your plugin modules.

  1. config.plugins.requireFromPath - The top one used for all plugins
  2. config.plugins.<plugin-id>.requireFromPath - Used for the specific plugin of <plugin-id>, overrides the one above
  3. config.plugins.<plugin-id>.module.requireFromPath - Used for the specific plugin of <plugin-id>, overrides the two above

For more information: check out require-from-path

Plugin timeout

To configure the plugin timeout, use Fastify's pluginTimeout option.

  "server": {
    "pluginTimeout": 10000

Uses the Fastify default if none is specified.

Example: fastify-static

Here's an example using the fastify-static plugin:

First, install the plugin as you normally would from npm:

npm i --save fastify-static

Then, add your plugin to the config plugins section.

  plugins: {
    "fastify-static": {
      enable: true,
      options: {
        root: process.cwd()
      priority: 210,
      requireFromPath: process.cwd()

Above config tells @xarc/fastify-server to require from CWD the module by its <plugin-id> "fastify-static" and register it as a plugin with Fastify. Options passes in the required root option to fastify-static.


The electrode server exports a single API.


electrodeServer(config, [decors], [callback])

  • config is the electrode server config

  • decors - Optional extra config or array of config. In case you have common config you want to put inside a dedicated module, you can pass them in here.

    • If it's an array like [ decor1, decor2, decor3 ] then each one is composed into the main config. ie: something similar to _.merge(mainConfig, decor1, decor2, decor3).
  • callback is an optional errback with the signature function (err, server)

    • where server is the Fastify server
  • Returns: a promise resolving to the Fastify server if callback is not provided

app decorator

Elecrode server also provides the app decorator on the server and request objects. The app object contains the fully merged final config.

handler: (request, reply) => {
  console.log("Listening on ", request.app.config.connection.port);

Enable compression

In Fastify compression can be achieved using @fastify/compress

      priority: 200,
        { global: true, encodings:['gzip'] }    

Currently, the following encoding tokens are supported, using the first acceptable token in this order:

* (no preference  @fastify/compress will use gzip)
identity (no compression)

Increase bodyLimit Size

    server: {
    bodyLimit : 1048576//new size limit


Make sure you sign the CLA. Checkout the contribution guide

To run tests

% npm i
% clap test

To run tests and coverage

% clap check

To run sample server

% npm run sample

Hit http://localhost:9000 Hit http://localhost:9000/html/hello.html to test static path.


Copyright 2016-present WalmartLabs

Licensed under the Apache License, Version 2.0.

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