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Awesome Open Source


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A core Pluggable framework based on koa.

Don't use it directly, see egg.


Directory structure

├── package.json
├── app.js (optional)
├── agent.js (optional)
├── app
|   ├── router.js
│   ├── controller
│   │   └── home.js
|   ├── extend (optional)
│   |   ├── helper.js (optional)
│   |   ├── filter.js (optional)
│   |   ├── request.js (optional)
│   |   ├── response.js (optional)
│   |   ├── context.js (optional)
│   |   ├── application.js (optional)
│   |   └── agent.js (optional)
│   ├── service (optional)
│   ├── middleware (optional)
│   │   └── response_time.js
│   └── view (optional)
|       ├── layout.html
│       └── home.html
├── config
|   ├── config.default.js
│   ├──
|   ├── config.test.js (optional)
|   ├── config.local.js (optional)
|   ├── config.unittest.js (optional)
│   └── plugin.js

Then you can start with code below

const Application = require('egg-core').EggCore;
const app = new Application({
  baseDir: '/path/to/app'
app.ready(() => app.listen(3000));


EggLoader can easily load files or directories in your egg project. In addition, you can customize the loader with low level APIs.


  • {String} baseDir - current directory of application
  • {Object} app - instance of egg application
  • {Object} plugins - merge plugins for test
  • {Logger} logger - logger instance,default is console

High Level APIs


Load config/plugin.js


Load config/config.js and config/{serverEnv}.js

If process.env.EGG_APP_CONFIG is exists, then it will be parse and override config.


Load app/controller


Load app/middleware


Load app/extend/application.js


Load app/extend/context.js


Load app/extend/request.js


Load app/extend/response.js


Load app/extend/helper.js


Load app.js, if app.js export boot class, then trigger configDidLoad


Load agent.js, if agent.js export boot class, then trigger configDidLoad


Load app/service

Low Level APIs


Retrieve application environment variable values via serverEnv. You can access directly by calling this.serverEnv after instantiation.

serverEnv description
default default environment
test system integration testing environment
prod production environment
local local environment on your own computer
unittest unit test environment


To get directories of the frameworks. A new framework is created by extending egg, then you can use this function to get all frameworks.


A loadUnit is a directory that can be loaded by EggLoader, cause it has the same structure.

This function will get add loadUnits follow the order:

  1. plugin
  2. framework
  3. app

loadUnit has a path and a type. Type must be one of those values: app, framework, plugin.

  path: 'path/to/application',
  type: 'app'


To get application name from package.json


Get the infomation of the application

  • pkg: package.json
  • name: the application name from package.json
  • baseDir: current directory of application
  • env: equals to serverEnv
  • HOME: home directory of the OS
  • root: baseDir when local and unittest, HOME when other environment


To load a single file. Note: The file must export as a function.

loadToApp(directory, property, LoaderOptions)

To load files from directory in the application.

Invoke this.loadToApp('$baseDir/app/controller', 'controller'), then you can use it by app.controller.

loadToContext(directory, property, LoaderOptions)

To load files from directory, and it will be bound the context.

// define service in app/service/query.js
module.exports = class Query {
  constructor(ctx) {
    // get the ctx

  get() {}

// use the service in app/controller/home.js
module.exports = function*() {
  this.body = this.service.query.get();

loadExtend(name, target)

Loader app/extend/xx.js to target, For example,

this.loadExtend('application', app);


Param Type Description
directory String/Array directories to be loaded
target Object attach the target object from loaded files
match String/Array match the files when load, default to **/*.js(if process.env.EGG_TYPESCRIPT was true, default to `[ '**/*.(js
ignore String/Array ignore the files when load
initializer Function custom file exports, receive two parameters, first is the inject object(if not js file, will be content buffer), second is an options object that contain path
caseStyle String/Function set property's case when converting a filepath to property list.
override Boolean determine whether override the property when get the same name
call Boolean determine whether invoke when exports is function
inject Object an object that be the argument when invoke the function
filter Function a function that filter the exports which can be loaded


EggCore record boot progress with Timing, include:

  • Process start time
  • Script start time(node don't implement an interface like process.uptime to record the script start running time, framework can implement a prestart file used with node --require options to set process.scriptTime)
  • Application start time
  • Load duration
  • require duration


Start record a item. If the item exits, end the old one and start a new one.

  • {String} name - record item name
  • {Number} [start] - record item start time, default is


End a item.

  • {String} name - end item name


Generate all record items to json

  • {String} name - record item name
  • {Number} start - item start time
  • {Number} end - item end time
  • {Number} duration - item duration
  • {Number} pid - pid
  • {Number} index - item index

Questions & Suggestions

Please open an issue here.



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