Backends

A backend with no front end needs no bundler of its own: build() from @zeroko-io/core bundles its entry, every dependency in it, and deploys it.

npm install -D @zeroko-io/core

// build.js, run by "build": "node build.js"
import { build } from "@zeroko-io/core"

await build({ entry: "src/index.ts" })

Its options are the SDK's, and assets, a directory of files to serve as they are.

Hono

A Hono app is a service as it is: its default export has fetch. The bindings are in c.env.

import type { Database } from "@zeroko-io/core"
import { Hono } from "hono"

const app = new Hono<{ Bindings: { DB: Database } }>()

app.post("/notes", async (c) => {
  const { text } = await c.req.json()
  const { lastRowId } = await c.env.DB.run("INSERT INTO notes (text) VALUES (?)", text)
  return c.json({ id: lastRowId }, 201)
})

export default app

Any other module whose default export has fetch(request, env, ctx) works the same way.

Express and Koa

Node's HTTP servers run through workerd's Node compatibility: node() makes a service of an app.

import { node } from "@zeroko-io/core/node"
import express from "express"

const app = express()
app.use(express.json())
app.get("/", (req, res) => res.json({ hello: "world" }))

export default node(app)

For Koa, node(app.callback()); a node:http server works too. An app that gets ready on its own (it waits for something before serving) goes as a function, called on the first request: a module can't wait for anything at its top level.

export default node(async () => {
  const app = await makeApp()
  return app
})

These apps don't get the bindings as arguments: read them from cloudflare:workers, where workerd keeps them.

import { env } from "cloudflare:workers"

app.get("/notes", async (req, res) => res.json(await env.DB.query("SELECT * FROM notes")))

What doesn't run

Fastify compiles its schemas into code at runtime, which a worker can't: it doesn't run on Zeroko, as on any workers runtime. Hono, Express and Koa do.