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LoopBack makes it easy to build modern applications that require complex integrations.


  • Fast, small, powerful, extensible core
  • Generate real APIs with a single command
  • Define your data and endpoints with OpenAPI
  • No maintenance of generated code


$ npm install --save @loopback/core

Basic Use

@loopback/core provides the foundation for your LoopBack app, but unlike previous versions, it no longer contains the implementation for listening servers.

For a typical example of how to create a REST server with your application, see the @loopback/rest package.

Advanced Use

Since @loopback/core is decoupled from the listening server implementation, LoopBack applications are now able to work with any component that provides this functionality.

// index.ts
import {Application} from '@loopback/core';
import {RestComponent} from '@loopback/rest';
import {GrpcComponent} from '@loopback/grpc';

const app = new Application({
  rest: {
    port: 3000,
  grpc: {
    port: 3001,
app.component(RestComponent); // REST Server
  // GRPC Server

  async function start() {
    // Let's retrieve the bound instances of our servers.
    const rest = await app.getServer<RestServer>('RestServer');
    const grpc = await app.getServer<GrpcServer>('GrpcServer');

    // Define all sorts of bindings here to pass configuration or data
    // between your server instances, define controllers and datasources for them,
    // etc...
    await app.start(); // This automatically spins up all your servers, too!
    console.log(`REST server running on port: ${rest.getSync('rest.port')}`);
    console.log(`GRPC server running on port: ${grpc.getSync('grpc.port')}`);

In the above example, having a GRPC server mounted on your Application could enable communication with other GRPC-enabled microservices, allowing things like dynamic configuration updates.



Run npm test from the root folder.


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