Skip to main content

How to Deploy a Serverless Function

In this tutorial, you will learn how to deploy functions or serverless workloads on Genezio. We'll cover the benefits, answer common questions, and provide detailed deployment steps.

Genezio is a Function-as-a-Service (FaaS) platform that simplifies cloud deployments and significantly reduces infrastructure costs.

Do I need to modify my source code? Make sure you export your function as a handler that will process events. Check out this section to see a code snippet.

Why Use Genezio?

Benefits of Using Genezio

  1. Faster Deployment: Genezio optimizes the deployment process, significantly reducing the time it takes to get your app live.
  2. Reduced costs: Thanks to Genezio’s efficient infrastructure the costs are significantly lower. Additionally, Genezio offers a more predictable pricing plan, avoiding the pitfalls of the typical “pay-as-you-go” model that can lead to unexpectedly high bills due to unwanted mistakes.
  3. Reliable and Scalable: No longer worry about PM2 and Docker. You write the code, and Genezio seamlessly scales it across multiple cores.
  4. Enhanced Security: Built-in security features and automatic updates protect your app against the latest threats without additional effort.
  5. Reduced Management Overhead: Focus on developing your app instead of managing servers and routine maintenance tasks.
  6. Easy Migration: Obtain all these advantages with minimal code changes.

How Does Genezio Handle High Traffic?

Genezio, being a Function as a Service (FaaS) platform, automatically scales your application based on traffic demands. It works by executing functions in response to events and can handle a large number of requests concurrently. This ensures your app remains responsive and performs well during traffic spikes.


1. Install genezio

Use your preferred package manager to install genezio:

npm install genezio -g

2. Export a function handler

You can implement and export a function handler following the next steps:

1. Initialize a New Node.js Project

Run the following command to initialize a new Node.js project in an empty directory:

npm init -y

2. Create a Function handler

Create a new file named app.mjs and add the following code:

export const handler = async (event) => {
console.log('Function was called');
const name = event.queryStringParameters?.name || 'George';
return {
statusCode: 200,
body: `Hello, ${name}! Welcome to Genezio Functions!`,

Deployment Guide

1. Create the Genezio Configuration File

Now, create a genezio.yaml file in the root directory of your project.

This file will contain the configuration needed to deploy your backend using Genezio. Here is an example configuration.

  1. You might need to replace the entry field with the name of your main application file.
  2. You might need to replace the path field with the path relative at genezio.yaml file.
  3. This example configuration works if genezio.yaml is in the same directory as your main application file.
# The name of the project.
name: functions-app
# The region where the project is deployed. Available regions: us-east-1, eu-central-1
region: us-east-1
# The version of the Genezio YAML configuration to parse.
yamlVersion: 2
# The root directory of the backend.
path: ./
# Information about the backend's programming language.
# The name of the programming language.
name: js
# The package manager used by the backend.
packageManager: npm
# Information about the backend's functions.
# The name (label) of the function.
- name: hello-world-function
# The path to the function's code.
path: ./
# The name of the function handler
handler: handler
# The entry point for the function.
entry: app.mjs

This configuration file specifies the project name, deployment region, and details about the backend.

4. Test Your App Locally

Before deploying your app, you can test it locally to ensure it's working correctly.

Run the following command in your terminal:

genezio local

In your terminal, you should be able to see all the local URLs of your functions. You can then test them in your browser or using a tool like Postman.

5. Deploy your project

Finally, deploy your project. A browser window will open, and you will be prompted to log in to your Genezio account and authorize the CLI to make the deployment. Run the following command in your terminal:

genezio deploy

If your application use environment variables, you can deploy them using the following command:

genezio deploy --env <path-to-your-env-file>

You need to deploy your environment variables single time. After that, you can deploy your project without the --env flag.

For more information about environment variables, you can check the official documentation.

Check the Deployed App

After deploying your application, you can visit it by navigating to the the URL provided either in the terminal or in the Genezio dashboard. The URL can be copied from the corresponding project's overview page.

Additionally, you can monitor and manage your app through the Genezio App Dashboard. The dashboard URL, also provided after deployment, allows you to access comprehensive views of your project's status and logs.

You can find this URL in the deployment output under the App Dashboard URL section.


We invite you to join our community on Discord for further information and help.

Happy Learning!