Application Build

Overview

Following the code checkout, your application enters the build phase. To simplify the process and remove the need for you to manage complex build configurations, we use a standardized container image in the background. This means you do not need to provide your own Dockerfile within your repository.

The only required configuration for the build process is that you specify a Node.js version constraint in the engines.node field of your package.json file. This instructs our platform to use the specified Node.js version for the build.

Node.js Version Selection

Our platform supports all current Node.js Long Term Support (LTS) versions. When a build is triggered, we read your specified version constraint and select the most recent, compatible Node.js image available.

For example, you can specify the following in your package.json:

This constraint indicates that your application requires a Node.js version of 22.15.0 or higher. Our platform will then select the most up-to-date Node.js 22 image that satisfies this requirement, ensuring your build benefits from the latest security patches and performance improvements within that major version.

This approach provides you with the flexibility to define your application's requirements while we handle the complexities of image selection and maintenance.

Node.js 20 Deprecation

Important Notice: Node 20 will be deprecated and removed from our list of supported major versions on May 4th, 2026. To ensure continued support and access to the latest features and security updates, please upgrade your Node.js version to 22 or 24 by updating your package.json file as follows:

For Node 22:

For Node 24: