AlabJS supports Deno Deploy via the alabjs/adapters/deno adapter. Deno Deploy runs your code at the edge in 35+ regions globally with zero cold starts.

How it works

Deno Deploy uses the standard Web Fetch API (Request / Response). AlabJS provides createDenoHandler which wraps your app in a compatible fetch handler — no H3 or Node.js HTTP involved.

Setup

Create an entry point file at the project root:

// main.ts
import { createDenoHandler } from "alabjs/adapters/deno";
import manifest from "./.alabjs/dist/route-manifest.json" with { type: "json" };

const handler = createDenoHandler(manifest, {});
Deno.serve(handler.fetch.bind(handler));

Build

alab build

Deploy

Install deployctl:

deno install -A jsr:@deno/deployctl

Deploy to Deno Deploy:

deployctl deploy --project=my-alabjs-app main.ts

On first deploy, deployctl will prompt you to link or create a Deno Deploy project.

Environment variables

Set secrets in the Deno Deploy dashboard under your project → Settings → Environment Variables. They are available via Deno.env.get() or the standard process.env polyfill:

const dbUrl = Deno.env.get("DATABASE_URL");

Local development with Deno

Test your Deno entry point locally:

deno run --allow-net --allow-read --allow-env main.ts

For the full dev experience (HMR, fast refresh), use alab dev with Node.js as usual and only use the Deno entry point for production deploys.

Limitations

Feature	Status
Streaming SSR	Supported (renderToReadableStream)
Server functions	Supported
Image optimization	Not available — Rust napi binary cannot run on Deno Deploy. Image requests are redirected to the original source URL.
File system access	Read-only via Deno.readFile — write access not available
PPR shells	Not available — .alabjs/ppr-cache/ is not deployed
Node.js built-ins	Available via Deno's Node compatibility layer

Image optimization workaround

Since the Rust binary can't run on Deno Deploy, use a CDN transform URL for images. Point /_alabjs/image requests to Cloudflare Images, ImageKit, or a similar service via a custom middleware.