AlabJS can be deployed to Cloudflare Workers for globally distributed edge rendering — your pages render in the data centre closest to each user with no cold starts.

Prerequisites

• A Cloudflare account
• Wrangler CLI: pnpm add -D wrangler

Build for Cloudflare

alab build

This produces:

• _worker.js — the Workers entry point
• _routes.json — tells Cloudflare which paths the Worker handles vs. which are static assets

Configure Wrangler

# wrangler.toml
name = "my-alabjs-app"
compatibility_date = "2025-09-01"
compatibility_flags = ["nodejs_compat"]

main = "_worker.js"

[assets]
directory = ".alabjs/dist/client"

The nodejs_compat flag enables Node.js built-ins (crypto, Buffer, etc.) in the Workers runtime.

Deploy

pnpm wrangler deploy

Environment variables

Set secrets via Wrangler:

wrangler secret put DATABASE_URL
wrangler secret put SESSION_SECRET

Access them in server functions via process.env — the Cloudflare adapter polyfills process.env from the Workers environment bindings.

KV and D1

Cloudflare bindings (KV, D1, R2, Durable Objects) are available in server functions via the Workers request context. Access them through the ctx parameter:

// app/posts/page.server.ts
import { defineServerFn } from "alabjs/server";

export const getPosts = defineServerFn(async (_, { env }) => {
  // env is the Cloudflare Workers env object
  const result = await env.DB.prepare("SELECT * FROM posts").all();
  return result.results;
});

Limitations

Feature	Status
Streaming SSR	Supported (Workers support ReadableStream)
Server functions	Supported
Image optimization	Limited — Cloudflare Images is recommended instead
Offline service worker	Supported
Node.js built-ins	Supported via nodejs_compat flag
File system access	Not available — use KV or R2 instead

Local development

Test your Cloudflare build locally with Wrangler's dev mode:

pnpm wrangler dev _worker.js --assets .alabjsjs/dist/client

This runs the exact same Workers runtime locally, including bindings. Use --remote to connect to your actual Cloudflare KV/D1 data.

Custom domains

After deploying, add a custom domain in the Cloudflare dashboard under Workers → your worker → Triggers → Custom Domains. No Nginx, no load balancer.

Pages vs Workers

AlabJS targets Workers (not Pages) for full server-side rendering flexibility. If you only need to serve static assets, use alab build --mode spa and deploy the spa/ output to Cloudflare Pages directly.