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Version: current

Falcon Server Env

This package delivers base classes and helpers for ApiDataSources and Extensions.


npm install @deity/falcon-server-env
yarn add @deity/falcon-server-env


To define your own extension (high-level data provider) - you would need to create a new package and export its main class:

// package.json - "name": "my-custom-falcon-extension" (it will be used in the config below)
const { Extension } = require('@deity/falcon-server-env');
module.exports = class CustomExtension extends Extension {
async getGraphQLConfig() {
return {
schema: [`
extend type Query {
customQuery(name: String): CustomResult
type CustomResult {
foo: String
resolvers: {
Query: {
customQuery: (...params) => this.api.customQuery(...params)

Check Extension API reference for more methods.

To define your own API class (low-level data provider) - you would need to create a new package and export its main class:

// package.json - "name": "my-custom-falcon-api" (it will be used in the config below)
const { ApiDataSource } = require('@deity/falcon-server-env');
module.exports = class CustomApi extends ApiDataSource {
async customQuery(obj, params, context, info) {
// perform any "params" transformation if need
// let's assume it will be set to { "name": "foo" }
const queryParams = params;
// GET request will be sent to https://example.com/custom-api-endpoint?name=foo
// this endpoint has to return { "foo": "some string" } type result
return this.get('custom-api-endpoint', queryParams);

Then in your project's config (server app) - you need to declare them and assign your API to your Extension:

"apis": {
"my-custom-api": {
"package": "my-custom-falcon-api",
"config": {
"host": "example.com",
"protocol": "https"
"extensions": {
"custom": {
"package": "my-custom-falcon-extension",
"config": {
"api": "my-custom-api"


falcon-server-env package provides a list of events, that are being handled by Falcon-Server app during the whole runtime.

In order to use events - Falcon-Server exposes eventEmitter property (instantiated from eventemitter2) and passes it to the following classes (and derived from these classes):

  • ApiDataSource and ApiContainer
  • Extension and ExtensionContainer
  • EndpointManager and EndpointContainer

To use the events within your class - you would need to import Events object and use it like:

const { Events } = require('@deity/falcon-server-env');
class MyExt extends Extension {
constructor(params) {
this.eventEmitter.on(Events.BEFORE_ENDPOINTS_REGISTERED, () => {
// do something

Async event handlers are supported!

To check the order of the events - you should set verboseEvents config key to true

Ask the community. #help

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