Install Moleculer

Moleculer can be installed with npm or yarn

$ npm i moleculer --save

Create your first microservice

This example shows how to create a small math service to add two numbers.

const { ServiceBroker } = require("moleculer");

const broker = new ServiceBroker();

name: "math",
actions: {
add(ctx) {
return Number(ctx.params.a) + Number(ctx.params.b);

// Call service
.then(() =>"math.add", { a: 5, b: 3 }))
.then(res => console.log("5 + 3 =", res))
.catch(err => console.error(`Error occured! ${err.message}`));
Try it in your browser!

Open this example on Runkit!

Create a Moleculer project

Use the Moleculer CLI tool to create a new Moleculer-based microservices project.

  1. Install moleculer-cli globally

    $ npm i moleculer-cli -g
  2. Create a new project (named moleculer-demo)

    $ moleculer init project moleculer-demo

    Press Y to all questions

  3. Open project folder

    $ cd moleculer-demo
  1. Start project

    $ npm run dev
  2. Open the http://localhost:3000/ link in your browser. It shows a start page which contains two links to call the greeter service via API gateway.


You have just created your first Moleculer-based microservices project! The next step is to check our examples or demo projects.