Deno

Railpack builds and deploys Deno applications with zero configuration.

Detection

Your project will be detected as a Deno application if a deno.json or deno.jsonc file exists in the root directory.

Versions

The Deno version is determined in the following order:

• Set via the RAILPACK_DENO_VERSION environment variable
• Defaults to 2

Configuration

Railpack builds your Deno application based on your project structure. The build process:

• Installs Deno
• Caches dependencies using deno cache
• Sets up the start command based on your project configuration

The start command is determined by looking for:

1. A main.ts, main.js, main.mjs, or main.mts file in the project root
2. If no main file is found, it will use the first .ts, .js, .mjs, or .mts file found in your project

The selected file will be run with deno run --allow-all.

Config Variables

Variable	Description	Example
RAILPACK_DENO_VERSION	Override the Deno version	1.41