Moleculer

Moleculer is a progressive microservices framework for Node.js.

Documentation: https://moleculer.services/docs

What's included

Promise-based solution
request-reply concept
support streams
support event driven architecture with balancing
built-in service registry & dynamic service discovery
load balanced requests & events (round-robin, random, cpu-usage, latency)
many fault tolerance features (Circuit Breaker, Bulkhead, Retry, Timeout, Fallback)
supports middlewares
supports versioned services
service mixins
built-in caching solution (memory, Redis)
pluggable transporters (TCP, NATS, MQTT, Redis, NATS Streaming, Kafka)
pluggable serializers (JSON, Avro, MsgPack, Protocol Buffer, Thrift)
pluggable validator
multiple services on a node/server
all nodes are equal, no master/leader node
parameter validation with fastest-validator
built-in health monitoring & metrics
official API gateway module and many other modules...

Installation

$ npm install moleculer --save

$ yarn add moleculer

Create your first microservice

This example shows you how to create a small service with an add action which can add two numbers and how to call it.

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

// Create a broker
let broker = new ServiceBroker({ logger: console });

// Create a service
broker.createService({
    name: "math",
    actions: {
        add(ctx) {
            return Number(ctx.params.a) + Number(ctx.params.b);
        }
    }
});

// Start broker
broker.start()
    // Call service
    .then(() => broker.call("math.add", { a: 5, b: 3 }))
    .then(res => console.log("5 + 3 =", res))
    .catch(err => console.error(`Error occurred! ${err.message}`));

Try it on Runkit

Create a Moleculer project

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

Install moleculer-cli globally
```
$ npm install moleculer-cli -g
```
Create a new project (named first-demo)
```
$ moleculer init project first-demo
```
Press Y on API Gateway & npm install
Open project folder
```
$ cd first-demo
```
Start project
```
$ npm run dev
```
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.

🎉Congratulations! Your first Moleculer based microservices project is created. Read our documentation to learn more about Moleculer.

Official modules

We have many official modules for Moleculer. Check our list!

Supporting

Moleculer is an open source project. It is free to use for your personal or commercial projects. However, developing it takes up all my free time to make it better and better on a daily basis. If you like Moleculer framework, please support it.

Thank you very much!